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 (2006). Briefing paper on transgenic trees--Agenda Point 26.1 -- SBSTTA 11 recommendation.

(2006). Quarterly report: Genomic tool development for the Fagaceae, Year 1 Quarter 1.

(2007). "Hearts and minds." Nat Biotechnol 25(2): 143-.

The nonprofit Pew Initiative on Food and Biotechnology is closing, but the need for an independent and neutral body to facilitate dialog on US biotech policy has never been greater.

Adams, J. M., G. Piovesan, et al. (2002). "The case for genetic engineering of native and landscape trees against introduced pests and diseases." Conserv Biol 16(4): 874-879.

Alston, J. M., R. E. Just, et al. (2006). What Have We Learned, and Where Do We Go from Here? Regulating Agricultural Biotechnology: Economics and Policy. R. E. Just and E. al, Springer: 701-722.

This chapter revisits the themes and issues explored in the book, drawing upon the content of its chapters. The main points are summarized, key results are synthesized, conclusions are drawn, and implications for policy and for further work by economists are suggested.

Amand, P. C. S., D. Z. Skinner, et al. (2000). "Risk of alfalfa transgene dissemination and scale-dependent effects." Theoretical and Applied Genetics 101(1-2): 107-114.

Pollen can function as a vehicle to disseminate introduced, genetically engineered genes throughout a plant population or into a related species. The measurement of the risk of inadvertent dispersal of transgenes must include the assessment of accidental dispersion of pollen. Factors to be considered include the rate of pollen spread, the maximal dispersion distance of pollen, and the spatial dynamics of pollen movement within seed production fields; none of which are known for alfalfa (Medicago sativa L.), an insect-pollinated crop species. Using a rare, naturally occurring molecular marker, alfalfa pollen movement was tracked from seed and hay production fields. Results indicated that leafcutter bees ((Megachile spp.) used in commercial seed production show a directional, non-random bias when pollinating within fields, primarily resulting in the movement of pollen directly towards and away from the bee domicile. Within-field pollen movement was detected only over distances of 4 m or less. Dispersal of pollen from alfalfa hay and seed production fields occurs at distances up to 1000 m. By examining widely dispersed, individual escaped alfalfa plants and their progeny using RAPD markers, gene movement among escaped alfalfa plants has been confirmed for distances up to 230 m. The outcrossing frequency for large fields was nearly 10-times greater than that of research-sized plots. A minimum isolation distance of 1557 m may be required to prevent gene flow in alfalfa. Data suggest that complete containment of transgenes within alfalfa seed or hay production fields would be highly unlikely using current production practices.

Ammann, D., A. Hilbeck, et al. (2007). "Procedure for the implementation of the precautionary principle in biosafety commissions." Journal of Risk Research 10(4): 487-501.

In order to fulfil their responsibilities under the precautionary principle, biosafety commissions should lay down guidelines concerning the understanding and application of this principle and work towards an operational procedure. With this contribution, we propose a step-wise procedure that aims to establish the understanding of the precautionary principle within biosafety commissions and to provide a methodological approach for the application of this principle to specific cases in the course of risk assessment. This approach is based on systematically investigating the consensus view within a group of 15 biosafety experts with the help of sets of checklists. For step 1, we propose a checklist of 13 criteria aimed at defining the understanding of the precautionary principle. For step 2, we propose 4 criteria for the decision on whether or not to use the precautionary principle. For step 3, 11 criteria for the use of the precautionary principle are presented. In step 4, additional criteria for specific applications could be included. In step 5, possible recommendations to decision-making authorities are proposed.

Ammitzboll, H. and R. Bagger Jorgensen (2006). "Hybridization between oilseed rape (Brassica napus) and different populations and species of Raphanus." Environ Biosafety Res 5(1): 3-13.

When cultivating genetically modified varieties, the spontaneous gene flow between crop and wild relatives could be of concern. We analyzed spontaneous hybridization between a transgenic male-sterile line of oilseed rape (Brassica napus, 2n = 38, AACC) and, as pollen donors, three European populations of wild radish (Raphanus raphanistrum, 2n = 18, Rr,Rr) and a variety of cultivated radish (Raphanus sativus, 2n = 18, RR). Seeds showed size and shape dimorphism that correlated to the frequency of hybrids. The offspring were scored morphologically and analyzed using DNA markers (inter-simple sequence repeats) to quantify hybrid frequencies. Seed set ranged from 0.4-1.2 seeds per pod, and 0.02-0.6 seeds per pod were confirmed as hybrids. The frequency of confirmed hybrids differed significantly among populations of R. raphanistrum. In the cross with a French population, all offspring were hybrids; in the cross with a Swiss population, 53% of the offspring were hybrids; and in the cross with a Danish population, only 2% of the offspring were found to be hybrids. The remaining offspring apparently belonged to two groups: the majority was B. napus-like plants, possibly of matromorphic origin, and a minority from the Danish cross seemed to carry fragments of the Raphanus genome. In the cross with a cultivated R. sativus, all offspring were found to be hybrids. This is the first report on spontaneous hybridization between B. napus and R. sativus. Hybrids from all cross-combinations had low pollen fertility (0-15%). If R. raphanistrum occurs where male-sterile B. napus is cultivated, large regional differences in hybridization frequencies between the species could complicate environmental risk assessment of transgenic oilseed rape.

Ammitzboll, H., T. N. Mikkelsen, et al. (2005). "Transgene expression and fitness of hybrids between GM oilseed rape and Brassica rapa." Environ Biosafety Res 4(1): 3-12.

Oilseed rape (Brassica napus) is sexually compatible with its wild and weedy relative B. rapa, and introgression of genes from B. napus has been found to occur over a few generations. We simulated the early stages of transgene escape by producing F1 hybrids and the first backcross generation between two lines of transgenic B. napus and two populations of weedy B. rapa. Transgene expression and the fitness of the hybrids were examined under different environmental conditions. Expression of the transgenes was analyzed at the mRNA level by quantitative PCR and found to be stable in the hybrids, regardless of the genetic background and the environment, and equal to the level of transcription in the parental B. napus lines. Vigor of the hybrids was measured as the photosynthetic capability; pollen viability and seed set per silique. Photosynthetic capability of first generation hybrids was found to be at the same level, or higher, than that of the parental species, whereas the reproductive fitness was significantly lower. The first backcross generation had a significantly lower photosynthetic capability and reproductive fitness compared to the parental species. This is the first study that examines transgene expression at the mRNA level in transgenic hybrids of B. napus of different genetic background exposed to different environmental conditions. The data presented clarify important details of the overall risk assessment of growing transgenic oilseed rape.

Andow, D. A. (2003). "UK farm-scale evaluations of transgenic herbicide-tolerant crops." Nature Biotechnology 21(12): 1453-1454.

Andow, D. A. and A. Hilbeck (2004). "Science-based risk assessment for nontarget effects of transgenic crops." Bioscience 54(7): 637-649.

Nontarget risk assessment for transgenic crops should be case specific, depending on the plant, the transgene, and the intended release environment. We propose an ecological risk-assessment model that preserves the strengths and avoids the deficiencies of two other commonly used models, the ecotoxicology and nonindigenous-species models. In this model, locally occurring nontarget species are classified into groups according to their ecological function. Within each group, ecological criteria arc used to select the species that are most likely to be affected by the transgenic crop. Initial experimental assessments are conducted in the laboratory and consist of two kinds of test: toxicity tests using purified transgene product, and whole-plant tests using intact transgenic plants. For nontarget natural enemy species, it will also be important to evaluate both direct bitrophic impacts and indirect tritrophic impacts.

Andow, D. A., G. L. Lovei, et al. (2006). "Ecological risk assessment for Bt crops." Nature Biotechnology 24(7): 749-751.

Andow, D. A. and C. Zwahlen (2006). "Assessing environmental risks of transgenic plants." Ecol Lett 9(2): 196-214.

By the end of the 1980s, a broad consensus had developed that there were potential environmental risks of transgenic plants requiring assessment and that this assessment must be done on a case-by-case basis, taking into account the transgene, recipient organism, intended environment of release, and the frequency and scale of the intended introduction. Since 1990, there have been gradual but substantial changes in the environmental risk assessment process. In this review, we focus on changes in the assessment of risks associated with non-target species and biodiversity, gene flow, and the evolution of resistance. Non-target risk assessment now focuses on risks of transgenic plants to the intended local environment of release. Measurements of gene flow indicate that it occurs at higher rates than believed in the early 1990s, mathematical theory is beginning to clarify expectations of risks associated with gene flow, and management methods are being developed to reduce gene flow and possibly mitigate its effects. Insect pest resistance risks are now managed using a high-dose/refuge or a refuge-only strategy, and the present research focuses on monitoring for resistance and encouraging compliance to requirements. We synthesize previous models for tiering risk assessment and propose a general model for tiering. Future transgenic crops are likely to pose greater challenges for risk assessment, and meeting these challenges will be crucial in developing a scientifically coherent risk assessment framework. Scientific understanding of the factors affecting environmental risk is still nascent, and environmental scientists need to help improve environmental risk assessment.

APHIS (2006). USDA APHIS seeks comments on environmental risk assessments: GE tall fescue and GE Italian ryegrass. ISB News Report: 11-11.

Environmental Assessment of GE Tall Fescue and

APHIS (2006). White paper: Perspective on creeping bentgrass, Agrostis stolonifera L: 1-91.

Creeping bentgrass (Agrostis stolonifera) has been utilized as a forage species for centuries, and as a turf species for many decades. It now occurs worldwide in temperate areas. However, basic information on Agrostis stolonifera from the non-agronomic biological and ecological literature had not previously been consolidated. Consequently, this white paper presents a general overview on Agrostis stolonifera biology and ecology as a native and naturalized species, with certain aspects focusing on the United States and Canada. This synthesis and summary provide perspective on Agrostis stolonifera and a pathway to the diverse literature1, to advance understanding, research and application.

APHIS (2007). "APHIS policy on responding to the low-level presence of regulated genetically engineered plant materials." Fed Register.

Arias, D. M. and L. H. Rieseberg (1994). "Gene Flow between Cultivated and Wild Sunflowers." Theoretical and Applied Genetics 89(6): 655-660.

With the development of transgenic crops, concern has been expressed regarding the possible escape of genetically- engineered genes via hybridization with wild relatives. This is a potential hazard for sunflowers because wild sunflowers occur as weeds in fields where cultivated sunflowers are grown and hybridization between them has been reported. In order to quantify the potential for gene escape, two experimental stands of sunflower cultivars were planted at two sites with different rainfall and altitude profiles. Populations of wild plants were planted at different distances from each cultivar stand. An allele homozygous in the cultivar (6Pgd-3-a), but absent in the wild populations, was used as a molecular marker to document the incidence and rate of gene escape from the cultivar into the wild populations of sunflowers. Three-thousand achenes were surveyed to determine the amount of gene flow from the cultivated to the wild populations. The marginal wild populations (3 m from the cultivar) showed the highest percentage (27%) of gene flow. Gene flow was found to decrease with distance; however, gene flow occurred up to distances of 1000 m from the source population. These data suggest that physical distance alone will be unlikely to prevent gene flow between cultivated and wild populations of sunflowers.

Armstrong, T. T., R. G. Fitzjohn, et al. (2005). "Transgene escape: what potential for crop-wild hybridization?" Mol Ecol 14(7): 2111-2132.

To date, regional surveys assessing the risk of transgene escape from GM crops have focused on records of spontaneous hybridization to infer the likelihood of crop transgene escape. However, reliable observations of spontaneous hybridization are lacking for most floras, particularly outside Europe. Here, we argue that evidence of interspecific reproductive compatibility derived from experimental crosses is an important component of risk assessment, and a useful first step especially where data from field observations are unavailable. We used this approach to assess the potential for transgene escape via hybridization for 123 widely grown temperate crops and their indigenous and naturalized relatives present in the New Zealand flora. We found that 66 crops (54%) are reproductively compatible with at least one other indigenous or naturalized species in the flora. Limited reproductive compatibility with wild relatives was evident for a further 12 crops (10%). Twenty-five crops (20%) were found to be reproductively isolated from all their wild relatives in New Zealand. For the remaining 20 crops (16%), insufficient information was available to determine levels of reproductive compatibility with wild relatives. Our approach may be useful in other regions where spontaneous crop-wild hybridization has yet to be well documented.

Arnaud, J. F., F. Viard, et al. (2003). "Evidence for gene flow via seed dispersal from crop to wild relatives in Beta vulgaris (Chenopodiaceae): consequences for the release of genetically modified crop species with weedy lineages." Proceedings of the Royal Society of London Series B-Biological Sciences 270(1524): 1565-1571.

Gene flow and introgression from cultivated to wild plant populations have important evolutionary and ecological consequences and require detailed investigations for risk assessments of transgene escape into natural ecosystems. Sugar beets (Beta vulgaris ssp. vulgaris) are of particular concern because: (i) they are cross-compatible with their wild relatives (the sea beet, B. vulgaris ssp. maritima); (ii) crop-to-wild gene flow is likely to occur via weedy lineages resulting from hybridization events and locally infesting fields. Using a chloroplastic marker and a set of nuclear microsatellite loci, the occurrence of crop-to-wild gene flow was investigated in the French sugar beet production area within a 'contact-zone' in between coastal wild populations and sugar beet fields. The results did not reveal large pollen dispersal from weed to wild beets. However, several pieces of evidence clearly show an escape of weedy lineages from fields via seed flow. Since most studies involving the assessment of transgene escape from crops to wild outcrossing relatives generally focused only on pollen dispersal, this last result was unexpected: it points out the key role of a long-lived seed bank and highlights support for transgene escape via man-mediated long-distance dispersal events.

Arriola, P. E. and N. C. Ellstrand (1996). "Crop-to-weed gene flow in the genus Sorghum (Poaceae): Spontaneous interspecific hybridization between johnsongrass, Sorghum halepense, and crop sorghum, S-bicolor." American Journal of Botany 83(9): 1153-1159.

The role of crop-to-weed gene flow is often controversial and overlooked. As a consequence, the likelihood of spontaneous crop-to-weed hybridization in most crop/weed systems is generally unknown. The lack of data relating to the formation of crop/weed hybrids has particular contemporary significance when considering the wide scale commercial release of transgenic crop plants and the potential for escape of engineered genes via crop-to-weed hybridization. We created an experimental system whereby we could examine the incidence and rate of spontaneous crop-to-weed hybridization between Sorghum bicolor and S, halepense, johnsongrass. An isozyme marker was used to identify hybrid plants through progeny testing. Incidence and rate of hybridization were highly variable with respect to weed distance from the crop, location of the study site, and year the study was performed. Crop/weed hybrids were detected at distances of 0.5-100 m from the crop. Interspecific hybridization can and does occur in this system at a substantial and measurable rate. Transgenes introduced into crop sorghum can be expected to have the opportunity to escape cultivation through interspecific hybridization with johnsongrass. Traits that prove to be beneficial to weeds possessing them can be expected to persist and spread. This is an issue that needs to be addressed when developing biosafety guidelines for the commercial release of transgenic sorghums.

Asakawa, Y., F. Fukumoto, et al. (1993). "Evaluation of the Impact of the Release of Transgenic Tomato Plants with Tmv Resistance on the Environment." Jarq-Japan Agricultural Research Quarterly 27(2): 126-136.

Studies on the evaluation of the impact of the release of the tomato plants with an introduced gene of TMV resistance on the environment were carried out from January, 1989, to January, 1992, mainly at the National Institute of Agro-Environmental Sciences (NIAES) in collaboration with the National Institute of Agrobiological Resources (NIAR) and the National Agriculture Research Center (NARC). Experiments were carried out according to the guidelines enacted by the Science and Technology Agency and the Ministry of Agriculture, Forestry and Fisheries. The following characteristics were compared between the original plants and transgenic plants: (1) growth characteristics such as plant height and vigor, (2) pollen dispersion based on fruit set on emasculated flowers, (3) kinds of chemical substances produced by plants such as allelochemicals in plant tissues, soil and air, (4) microorganism flora in soil, (5) overwintering ability, (6) ability to become a weed, (7) the amount of Agrobacterium on plants, and (8) kinds of flower- visiting-insects. Cultivation was safely carried out. Since no harmful impact on the environment where the transgenic tomato plants had been cultivated was detected, it is suggested that this tomato strain can be cultivated in an open field. The TMV resistance was maintained throughout generations. These transgenic tomato plants were cultivated in an ordinary field in the summer of 1992 in the campus of the NIAES.

Aslaksen, I. and A. I. Myhr (2007). ""The worth of a wildflower": Precautionary perspectives on the environmental risk of GMOs." Ecological Economics 60(3): 489-497.

How much is a wildflower worth? inspired by "The worth of a songbird" by Funtowicz and Ravetz [Funtowicz, S.O., Ravetz, J.R., 1994. The worth of a songbird: ecological economics as a post-normal science. Ecological Economics 10, 197-207] we use the value of a wildflower as symbol of the complexity of evaluating environmental qualities and risks. We critically discuss the application of cost-benefit analysis in evaluating environmental impacts of adoption of genetically modified organisms (GMOs). We argue that cost-benefit analysis should be supplemented with other methods, such as processes for assessing uncertainty, accommodation of scientific disagreements, and integration of stakeholders' interests and perspectives. A more inclusive perspective is to develop precautionary approaches that recognize the multidimensional nature of environmental qualities and risks, such as irreplaceability, irreversibility, uncertainty and complexity. Precautionary approaches can contribute to develop a stronger environmental responsibility within the framework of rational self-interest. (c) 2006 Elsevier B.V. All rights reserved.

Assuncao, R. and C. M. Jacobi (1999). "Optimal sampling designs for studies of gene flow - A challenging trade-off: A reply to Klein and Laredo." Evolution 53(6): 2005-2007.

Astoin, M. F., J. Champolivier, et al. (2000). "Evaluation of the impact of flows of tolerant transgenic organisms to various broad-spectrum herbicides." Ocl-Oleagineux Corps Gras Lipides 7(4): 345-349.

Given the characterisation and evaluation of the gene flow from oilseed rape done by INRA, CNRS and Cetiom, the present paper aims to investigate the possible agro-environmental impacts of gene flow from herbicide-tolerant genetically-modified (CM) oilseed rape (seed loss outside and inside the field, pollen dispersal, interspecific hybridization). We identified two main impacts of the release of such varieties in French agricultural systems: the possible questioning of CM content norms for the harvest of non-GM rape fields, and of the long-term effectiveness of such weed control strategies through the development of tolerant weeds (oilseed rape and hybrids). This text is an extract from a report that summarises French research on gene flow carried out by Cetiom towards the end of the two-year French moratorium on genetically-modified oilseed rape and sugar beet.

Auer, C. A. (2003). "Tracking genes from seed to supermarket: techniques and trends." Trends Plant Sci 8(12): 591-597.

Analytical techniques to track plant genes in the environment and the food chain are essential for environmental risk assessment, government regulation and production and trade of genetically modified (GM) crops. Here, I review laboratory techniques to track plant genes during pre-commercialization research on gene flow and post-commercialization detection, identification and quantification of GM crops from seed to supermarket. At present, DNA- and protein-based assays support both activities but the demand for fast, inexpensive, sensitive methods is increasing. Part of the demand has been generated by stringent food labeling and traceability regulations for GM crops. The increase in GM crops, changes in GM crop design, evolution of government regulations and adoption of risk-assessment frameworks will continue to drive development of analytical techniques.

Baack, E. J. (2006). "Engineered crops: transgenes go wild." Curr Biol 16(15): R583-584.

Genetically modified Agrostis stolonifera has escaped from cultivation. For the first time, a herbicide-resistant perennial weed has established itself in wild populations.

Bailar, J. C., III and A. J. Bailer (2001). "Environment and health: 9. The science of risk assessment." CMAJ 164(4): 503-506.

Potential hazards surround us at home, in the workplace, in our cars and even in health care facilities. Given exposure to these hazards, we may want to evaluate the risk that an adverse event will occur or that it will occur at some level of severity. In this article we introduce some concepts about risk and how it can be assessed, comment on the nature of hazards and the uncertainties inherent in the risk assessment process, and show how risk assessment affects the management of these hazards. Most of our discussion is in terms of chemical carcinogenesis, but the principles apply to the full range of threats to human health and survival.

Bakshi, A. (2003). "Potential adverse health effects of genetically modified crops." J Toxicol Environ Health B Crit Rev 6(3): 211-225.

Genetically modified crops have the potential to eliminate hunger and starvation in millions of people, especially in developing countries because the genetic modification can produce large amounts of foods that are more nutritious. Large quantities are produced because genetically modified crops are more resistant to pests and drought. They also contain greater amounts of nutrients, such as proteins and vitamins. However, there are concerns about the safety of genetically modified crops. The concerns are that they may contain allergenic substances due to introduction of new genes into crops. Another concern is that genetic engineering often involves the use of antibiotic-resistance genes as "selectable markers" and this could lead to production of antibiotic-resistant bacterial strains that are resistant to available antibiotics. This would create a serious public health problem. The genetically modified crops might contain other toxic substances (such as enhanced amounts of heavy metals) and the crops might not be "substantially equivalent" in genome, proteome, and metabolome compared with unmodified crops. Another concern is that genetically modified crops may be less nutritious; for example, they might contain lower amounts of phytoestrogens, which protect against heart disease and cancer. The review of available literature indicates that the genetically modified crops available in the market that are intended for human consumption are generally safe; their consumption is not associated with serious health problems. However, because of potential for exposure of a large segment of human population to genetically modified foods, more research is needed to ensure that the genetically modified foods are safe for human consumption.

Barton, J. E. and M. Dracup (2000). "Genetically Modified Crops and the Environment." Agron J 92(4): 797-803.

Genetic modification (GM) of crops provides new crop management options (production traits) and crops with industrial, pharmaceutical, and neutraceutical applications are likely to follow. The environmental benefits and risks of growing GM crops have drawn considerable, often polarized debate. This review seeks a balanced appraisal of environmental issues, and looks at principles associated with several GM production traits. Environmental assessment needs to consider the nature of the introduced trait, in the context of the biology of the plant and the environment it will be grown in (e.g., prospects of gene flow into other species). Interactions with the target ecosystem, including the possibility of cummulative impacts from organisms already released into the ecosystem (e.g., prospects for gene pyramiding) need to also be included in assessments. Current agricultural management practices and ecosystems have their own impacts on the environment, and it is against this background that the benefits and risks of releasing GM organisms should be judged. Before release, data collection on impacts of GMOs is temporally and spatially constrained, so caution must be exercised in decision making. Potential impacts also need to be monitored after release and the post-release monitoring framework needs scope to identify unforeseen impacts. The environmental sustainability of using GMOs will depend largely on wise management practices and monitoring must provide appropriate data to support continuing adaptation of management and regulation of GMOs.

Bartsch, D., U. Brand, et al. (2001). "Biosafety of hybrids between transgenic virus-resistant sugar beet and Swiss chard." Ecological Applications 11(1): 142-147.

One important issue of biosafety research is whether gene flow from transgenic crops to nontransgenic relatives causes unwanted effects. We carried out field trials with hybrids between transgenic sugar beets, and a close cultivated relative, Swiss chard. This hybrid also acts as a model for "weed beet" hybrids between sugar beet and wild/weed beet (Beta vulgaris ssp. maritima). Transgenic beets with beet necrotic yellow vein virus (BNYVV) coat protein (cp), phosphinothricin- acetyl-transferase (bar), and neomycin-phospho-transferase (nptII) genes were hand-crossed to Swiss chard. The resulting Fl plants and controls were grown at two different BNYVV infestation levels and three different competitive conditions with Chenopodium album. Transgenic hybrids had consistently higher biomass than controls under high background BNYVV infestation, and consistently lower biomass than controls under low background infestation. The transgenic hybrids had a significantly lower rate of bolting than controls at all sites. Competition with Ch. album always had a strong negative influence on the performance of all genotypes. We conclude that ecological implications due to the introduction and spread of virus-resistant transgenic hybrids will be observed only in those feral Swiss chard and wild beet populations where fitness is significantly influenced by high infestations of BNYVV.

Bartsch, D., J. Cuguen, et al. (2003). "Environmental implications of gene flow from sugar beet to wild beet--current status and future research needs." Environ Biosafety Res 2(2): 105-115.

Gene flow via seed or pollen is a basic biological process in plant evolution. The ecological and genetic consequences of gene flow depend on the amount and direction of gene flow as well as on the fitness of hybrids. The assessment of potential risks of transgenic plants should take into account the fact that conventional crops can often cross with wild plants. The precautionary approach in risk management of genetically modified plants (GMPs) may make it necessary to monitor significant wild and weed populations that might be affected by transgene escape. Gene flow is hard to control in wind-pollinated plants like beet (Beta vulgaris). In addition, wild beet populations potentially can undergo evolutionary changes which might expand their geographical distribution. Unintended products of cultivated beets pollinated by wild beets are weed beets that bolt and flower during their first year of planting. Weed beets cause yield losses and can delay harvest. Wild beets are important plant genetic resources and the preservation of wild beet diversity in Europe has been considered in biosafety research. We present here the methodology and research approaches that can be used for monitoring the geographical distribution and diversity of Beta populations. It has recently been shown that a century of gene flow from Beta vulgaris ssp. vulgaris has not altered the genetic diversity of wild Beta vulgaris L. ssp. maritima (L.) Arcang. in the Italian sugar beet seed production area. Future research should focus on the potential evolution of transgenic wild beet populations in comparison to these baseline data. Two monitoring models are presented describing how endpoints can be measured: (1) "Pre-post" crop commercialization against today's baseline and (2) "Parallel" to crop commercialization against GMP free reference areas/ populations. Model 2 has the advantage of taking ongoing changes in genetic diversity and population dynamics into account. Model 1 is more applicable if gene flow is so strong that most areas/populations contain GMPs. Important traits that may change the ecology of populations are genes that confer tolerance to biotic and abiotic stress. An assessment of environmental effects can realistically only be based on endpoints and consequences of gene introgression, which may include economic values of biodiversity in littoral and other ecosystems containing wild beet. In general, there is still a great need to harmonize worldwide monitoring systems by the development of appropriate methods to evaluate the environmental impact of introgressed transgenes.

Bartsch, D., M. Lehnen, et al. (1999). "Impact of gene flow from cultivated beet on genetic diversity of wild sea beet populations." Molecular Ecology 8(10): 1733-1741.

Gene flow and introgression from cultivated plants may have important consequences for the conservation of wild plant populations. Cultivated beets (sugar beet, red beet and Swiss chard: Beta vulgaris ssp. vulgaris) are of particular concern because they are cross-compatible with the wild taxon, sea beet (B.vs. ssp. maritima). Cultivated beet seed production areas are sometimes adjacent to sea beet populations; the numbers of flowering individuals in the former typically outnumber those in the populations of the latter. In such situations, gene flow from cultivated beets has the potential to alter the genetic composition of the nearby wild populations. In this study we measured isozyme allele frequencies of 11 polymorphic loci in 26 accessions of cultivated beet, in 20 sea beet accessions growing near a cultivated beet seed production region in northeastern Italy, and 19 wild beet accessions growing far from seed production areas. We found one allele that is specific to sugar beet, relative to other cultivated types, and a second that has a much higher frequency in Swiss chard and red beet than in sugar beet. Both alleles are typically rare in sea beet populations that are distant from seed production areas, but both are common in those that are near the Italian cultivated beet seed production region, supporting the contention that gene flow from the crop to the wild species can be substantial when both grow in proximity. Interestingly the introgressed populations have higher genetic diversity than those that are isolated from the crop. The crop-to-wild gene flow rates are unknown, as are the fitness consequences of such alleles in the wild. Thus, we are unable to assess the long- term impact of such introgression. However, it is clear that gene now from a crop to a wild taxon does not necessarily result in a decrease in the genetic diversity of the native plant.

Bartsch, D. and M. PohlOrf (1996). "Ecological aspects of transgenic sugar beet: Transfer and expression herbicide resistance in hybrids with wild beets." Euphytica 91(1): 55-58.

An increasing number of genetically engineered cultivars of several crops is being experimentally released into the environment. In future, crops with new transgenic traits will probably play an important role in agricultural practice. The long-term effect of transgenes on community ecology will depend on the distribution and establishment of transgenic plants in the wild, on the sexual transfer of their new genes to the environment and on the potential ecological impact of the transgenic trait. The starting point was the use of transgenic sugar beet lines, Beta vulgaris subspec. vulgaris var. altissima DOLL (Helm 1957), with transgenes coding for rhizomania and herbicide (BASTA(R)) resistance. The first two questions to answer were: Can the transgenes be transferred via pollen to wild beets, Beta vulgaris subspec. maritima (L.) ARCANG. or cultivated relatives such as red beet or spinach beet and are they expressed in the hybrids? Can transgenes be monitored in young Beta vulgaris-hybrids? The experimental transfer of transgenes was conducted in 1993 at a field location in northern Germany. The beets were hand-pollinated with transgenic pollen. In a non destructive biotest, the hybrid seedlings were tested for herbicide resistance. Transgenic plants showed no noxious phenotypic effects whereas control plants developed leaf necroses. All herbicide resistant hybrids within the biotest were assumed to be transgenic.

Bartsch, D. and M. Schmidt (1997). "Influence of sugar beet breeding on populations of Beta vulgaris ssp. maritima in Italy." Journal of Vegetation Science 8(1): 81-84.

It is highly probable that transgenic cultivars of sugar beet may influence wild beets in the seed-production-area of northern Italy. For this reason a survey of the local wild beet populations and their habitat characteristics was conducted in 1994/1995, i.e. before transgenic beets and their offspring could have become established. Wild beets (Beta vulgaris ssp. maritima) were found at 21 locations between Trieste and Cesenatico, as part of the natural littoral vegetation classified as Atriplicetum tatarici (Cakiletea maritimae) and Crithmetum (Crithmo-Staticetea). The analysis of phenotypic attributes leads to a division into three different subpopulations. Greenhouse studies on the morphology and life- cycle attributes demonstrated actual gene flow between conventional seed beet and the examined wild beet population.

Bartsch, D. and I. Schuphan (2002). "Lessons we can learn from ecological biosafety research." J Biotechnol 98(1): 71-77.

The last decade has seen an increasing number of biosafety related publications focusing on transgenic organisms. Recent extensive field studies suggest that harmful laboratory effects on non-target organisms rarely occur in the environment. Moreover, biosafety studies typically show no difference in hybridisation between genetically modified plants (GMPs) or non-GMPs and related wild species. Since risk is a product of both exposure and hazard, biosafety research should clearly not only target gene flow exposure but specifically concentrate on expected hazards emerging from successful transgene flow to wild relatives of GMPs. Generally, transgenic plants behave in an ecologically similar manner to non-GMPs if the modified trait confers a neutral advantage under environmental or experimental conditions. However, GMPs perform better than non-GMPs if the new phenotype is challenged by conditions ecologically advantageous for the modified trait. Since biosafety research is a laborious process it will have to concentrate resources on thoughtful, thorough experiments, and target ecologically 'riskier' organisms. So far, we have no evidence that the use of GMPs contradicts sustainable agriculture and nature conservation per se.

Belt, H. v. d. and B. Gremmen (2002). "Between precautionary principle and "sound science": distributing the burdens of proof." Journal of agricultural & environmental ethics 15: 103-122.

Bennett, R., R. Phipps, et al. (2004). "Environmental and human health impacts of growing genetically modified herbicide-tolerant sugar beet: a life-cycle assessment." Plant Biotechnol J 2(4): 273-278.

There is ongoing debate concerning the possible environmental and human health impacts of growing genetically modified (GM) crops. Here, we report the results of a life-cycle assessment (LCA) comparing the environmental and human health impacts of conventional sugar beet growing regimes in the UK and Germany with those that might be expected if GM herbicide-tolerant (to glyphosate) sugar beet is commercialized. The results presented for a number of environmental and human health impact categories suggest that growing the GM herbicide-tolerant crop would be less harmful to the environment and human health than growing the conventional crop, largely due to lower emissions from herbicide manufacture, transport and field operations. Emissions contributing to negative environmental impacts, such as global warming, ozone depletion, ecotoxicity of water and acidification and nutrification of soil and water, were much lower for the herbicide-tolerant crop than for the conventional crop. Emissions contributing to summer smog, toxic particulate matter and carcinogenicity, which have negative human health impacts, were also substantially lower for the herbicide-tolerant crop. The environmental and human health impacts of growing GM crops need to be assessed on a case-by-case basis using a holistic approach. LCA is a valuable technique for helping to undertake such assessments.

Bensasson, D., J. L. Boore, et al. (2004). "Genes without frontiers?" Heredity 92(6): 483-489.

For bacteria, the primary genetic barrier against the genetic exchange of DNA that is not self-transmissible is dissimilarity in the bacterial DNA sequences concerned. Genetic exchange by homologous recombination is frequent among close bacterial relatives and recent experiments have shown that it can enable the uptake of closely linked nonhomologous foreign DNA. Artificial vectors are mosaics of mobile DNA elements from free-living bacterial isolates and so bear a residual similarity to their ubiquitous natural progenitors. This homology is tightly linked to the multitude of different DNA sequences that are inserted into synthetic vectors. Can homology between vector and bacterial DNA enable the uptake of these foreign DNA inserts? In this review we investigate pUC18 as an example of an artificial vector and consider whether its homology to broad host-range antibiotic resistance transposons and plasmid origins of replication could enable the uptake of insert DNA in the light of studies of homology-facilitated foreign DNA uptake. We also discuss the disposal of recombinant DNA, its persistence in the environment and whether homologies to pUC18 may exist in naturally competent bacteria. Most DNA that is inserted into the cloning site of artificial vectors would be of little use to a bacterium, but perhaps not all.

Benton, T. G. (2007). "Ecology. Managing farming's footprint on biodiversity." Science 315(5810): 341-342.

Berenbaum, M. R. and M. Berenbaum (2001). "Interpreting the scientific literature. Differences in the scientific and lay communities." Plant Physiol 125(2): 509-512.

That the lay public can react differently to the scientific literature than does the scientific community was dramatically demonstrated recently in the context of genetically manipulated organisms. The journal Nature, a high-profile journal with a reputation in both the lay and scientific communities for quality, includes, along with full-length reports, a section called "Scientific Correspondence," articles that are preliminary in nature. On May 20, 1999, a scientific correspondence appeared by John E. Losey, Linda S. Rayor, and Maureen E. Carter, titled "Transgenic pollen harms monarch larvae." This short paper, less than a page in length and accompanied by only a single two-part figure, reported the results of a laboratory study in which pollen from corn (Zea mays) plants containing genetic material from Bacillus thuringiensis (Bt) was applied to leaves of milkweed (Asclepias curassavica) and administered to 25 larvae of the monarch butterfly (Danaus plexippus). Survival, weight gain, and proportion of leaf area consumed by larvae consuming untreated milkweed leaves were observed after 4 d and compared with that of larvae consuming milkweed leaves treated with corn pollen from an "unrelated, untransformed hybrid." These authors reported that survival, consumption rate, and weight gain were lowest on foliage treated with Bt pollen. These authors then suggested that their results had "potentially profound implications for the conservation of monarch butterflies" due to the fact that milkweed plants, exclusive hosts for monarch larvae, can frequently be found in the midwestern United States around the perimeters of corn fields and thus, depending upon timing, "may be within range of corn pollen deposition" (Losey et al., 1999).

Bergmans, H. (2006). "Basic framework for risk assessment for transgenic plants developed by the OECD: 20 years after the OECD "Blue Book"." Environ Biosafety Res 5(4): 213-218.

Bertoni, G. and P. A. Marsan (2005). "Safety risks for animals fed genetic modified (GM) plants." Vet Res Commun 29 Suppl 2: 13-18.

GM plants are widely grown all over the world, but many constraints still tend to discourage their use in Europe. Potential risks suggested to be associated with the use of GM are unexpected gene effects, allergenic potential, antibiotic resistance, gene flow. GM feed safety is presently evaluated by adopting the concept of GM substantial equivalence, by comparison with non-GM isogenic crops. Comparison is based on a wide spectrum of chemical components and on livestock performance. From the available experimental data, currently utilized GM plants appear safe and show no effects on animals or animal products. Hence, although they potentially exist, safety risks caused by the use of GM plants appear to be so low as be negligible in comparison with their potential benefits, if appropriately designed. GM plants represent a valuable option for future breeding, to increase yield while reducing the use of pesticides, improve plant adaptation to unfavourable environments, and produce better quality crops, also from a nutritional point of view. Nonetheless, GM crops are novel foods and the assessment of their safety using a scientific sound approach seems essential to protect the environment, as well as the health of humans and livestock.

Birch, A. N. E., B. S. Griffiths, et al. (2007). "The role of laboratory, glasshouse and field scale experiments in understanding the interactions between genetically modified crops and soil ecosystems: A review of the ECOGEN project." Pedobiologia 51(3): 251-260.

The interactions of genetically modified (GM) crops with soil species and ecosystems is complex, requiring both specific and broad spectrum assessments. In the ECOGEN project we undertook experiments at three scales of increasing complexity, using Bt maize expressing the Cry1Ab protein from Bacillus thuringiensis as an example. Test species were selected for laboratory-scale experiments to represent taxonomic groups that we could also monitor at glasshouse and field scales (e.g., nematodes, protozoa, micro-arthropods, earthworms, and snails). In the laboratory, single species were exposed to purified Cry1Ab protein or to Bt maize leaf powder incorporated into simplified diets under controlled conditions. In the glasshouse, multiple test species and soil microbial. communities taken from ECOGEN's field sites were exposed to Bt maize plants growing under glasshouse or mesocosm conditions. In the field, evaluations were conducted on our selected indicator groups over multiple sites and growing seasons. Field evaluation included assessment of effects due to the local environment, crop type, seasonal variation and conventional crop management practice (tillage and pesticide use), which cannot be assessed in the glasshouse. No direct effects of Cry1Ab protein or Bt leaf residues were detected on our laboratory test organisms, but some significant effects were detected in the glasshouse. Total nematode and protozoan numbers increased in field soil under Bt maize relative to conventional maize, whilst microbial community structure and activity were unaffected. Field results for the abundance of nematodes and protozoa showed some negative effects of Bt maize, thus contradicting the glasshouse results. However, these negative results were specific to particular field sites and sampling times and therefore were transient. Taking the overall variation found in maize ecosystems at different sites into account, any negative effects of Bt maize at field scale were judged to be indirect and no greater than the impacts of crop type, tillage and pesticide use. Although the ECOGEN results were not predictive between the three experimental scales, we propose that they have value when used with feedback loops between the scales. This holistic approach can used to address questions raised by results from any level of experimentation and also for putting GM crop risk:benefit into context with current agricultural practices in regionally differing agro-ecosystems.

Boudry, P., M. Morchen, et al. (1993). "The Origin and Evolution of Weed Beets - Consequences for the Breeding and Release of Herbicide-Resistant Transgenic Sugar- Beets." Theoretical and Applied Genetics 87(4): 471-478.

Populations of weed beets have expanded into European sugar beet production areas since the 1970s, thereby forming a serious new weed problem for this crop. We sampled seeds in different French populations and studied mitochondrial DNA, chloroplast DNA and life-cycle variability. Given the maternal inheritance of the mitochondrial and chloroplastic genomes and the nuclear determinism of the annual habit, we were able to determine the maternal origin and evolution of these weed beet populations. Our study shows that they carry the dominant allele ''B'' for annual habit at high frequency. The main cytoplasmic DNA type found in northern weed beet populations is the cytoplasmic male-sterile type characteristic of sugar beets. We were able to determine that these populations arise from seeds originating from the accidental pollinations of cultivated beets by adventitious beets in the seed production area, which have been transported to the regions where sugar beets are cultivated. These seeds are supposedly the origin of the weed forms and a frequently disturbed cultivated environment has selected for annual habit and early flowering genotypes. We discuss the consequences of the weed beet populations for the breeding, seed production and release of herbicide-resistant transgenic sugar beets.

Bourguet, D., M. T. Bethenod, et al. (2000). "Gene flow in the European corn borer Ostrinia nubilalis: implications for the sustainability of transgenic insecticidal maize." Proceedings of the Royal Society of London Series B-Biological Sciences 267(1439): 117-122.

Strategies proposed for delaying resistance to Bacillus thuringiensis toxins expressed by transgenic maize require intense gene flow between individuals that grew on transgenic and on normal (referred to as refuges) plants. To investigate gene flow in the European corn borer, Ostrinia nubilalis (Hubner), the genetic variability at 29 sampled sites from France was studied by comparing allozyme frequencies at six polymorphic loci. Almost no deviations from Hardy-Weinberg expectations occurred, and a high stability of allelic distribution was found among samples collected in the same site over two or three different generations, indicating a high stability of the genetic structure over time. The overall genetic differentiation was low at the region and whole country level, suggesting a high and homogeneous gene flow. These results are discussed in relation to the sustainability of transgenic insecticidal maize.

Bradford, K. J., N. Gutterson, et al. (2005). "Response." Nat Biotechnol 23(7): 787-789.

Bradshaw, A. H. and S. H. Strauss (2001). "Plotting a course for GM forestry." Nat Biotechnol 19(12): 1103-1104.

Brodsgaard, H. F., C. J. Brodsgaard, et al. (2003). "Environmental risk assessment of transgene products using honey bee (Apis mellifera) larvae." Apidologie 34(2): 139-145.

An environmental concern regarding the cultivation of transgenic crop plants is their effect on non-target organisms. Honey bees are obvious non-target arthropods to be included in a risk assessment procedure but due to their complex social behaviour, testing transgene products on individual bees is not possible in bee colonies. We employed a laboratory larval rearing technique to test the impacts of such transgene products on honey bees. A serine proteinase inhibitor ( Kunitz Soybean Trypsin Inhibitor, SBTI), that is a source of insect resistance in transgenic plants, was used as a model insecticidal protein on honey bee larvae reared individually in the laboratory. The addition of 1.0% SBTI (w:w of total protein) to the larval diet created significant additional larval mortality, slowed juvenile development and significantly decreased adult body mass. Our results suggest that the larval rearing technique can be used to monitor direct side-effects of transgene products on individual honey bee larvae.

Bruce, D. (2002). "Finding a balance over precaution." Journal of agricultural & environmental ethics 15: 7-16.

Bruggemann, E. P. (1993). "Environmental Safety Issues for Genetically-Modified Animals." Journal of Animal Science 71: 47-50.

Organisms modified by the techniques of modern biotechnology may differ significantly from normal organisms or organisms modified by other methods. Before transgenic organisms are introduced into the environment, the potential environmental effects should be assessed. In general, modification of ecologically important traits in undomesticated species presents the greatest environmental risk. Transgenic livestock probably pose low risk to the environment. Transgenic fish and live virus-based vaccines pose greater risks and present challenging questions for environmental risk assessment.

Brule-Babel, A. L., C. J. Willenborg, et al. (2006). "Modeling the Influence of Gene Flow and Selection Pressure on the Frequency of a GE Herbicide-Tolerant Trait in Non-GE Wheat and Wheat Volunteers." Crop Sci 46(4): 1704-1710.

Different types of transgenic wheat (Triticum aestivum L.) will be ready for commercialization within the next decade, including varieties with higher yields, greater tolerance to biotic and abiotic stresses, and resistance to herbicides. The release of genetically engineered (GE) wheat may require segregation of GE and non-GE wheat to satisfy international markets. Before GE wheat is released, it is important to understand the movement of a GE trait within the agronomic production system. This study evaluated the effects of gene flow and selection pressure on the frequency of a GE trait (herbicide tolerance) in non-GE wheat and wheat volunteers. Gene flow of GE traits to non-GE wheat is inevitable through pollen or seed movement. When a GE trait does not confer a selective advantage in the production system, the frequency of the GE trait within non-GE wheat will be a function of the rate of gene flow. Low rates of gene flow will lead to low levels of the GE trait in the non-GE crop. With repeated gene flow events, the frequency of the GE trait may slowly increase in the non-GE crop. When the GE trait has a selective advantage, the frequency of the GE trait will increase rapidly in volunteer populations of the non-GE crop. Herbicide tolerance is an example of a GE trait that provides a high selective advantage when the herbicide is applied in the production system. Predictive models show that even with very low rates of initial gene flow, frequent applications of a highly effective herbicide will quickly increase the frequency of the herbicide-tolerant (HT) GE trait in volunteer populations. This has negative implications for control of volunteers and the ability to maintain tolerance levels of GE traits in non-GE wheat crops.

Brunner, A. M., B. Goldfard, et al. (2003). Controlling maturation and flowering for forest tree domestication. Transgenic Plants: Current Innovations and Future Trends. C. N. Stewart, Jr. Wymondham, UK, Horizon Scientific Press: 9-44.

Brunner, A. M., J. Li, et al. (2007). "Genetic containment of forest plantations." Tree Genetics and Genomes In press.

Dispersal of pollen, seeds, or vegetative propagules from intensively bred, exotic, or recombinant DNA modified forest plantations may cause detrimental or beneficial ecological impacts on wild or managed ecosystems. Insertion of genes designed to prevent or substantially reduce dispersal could reduce the risk and extent of undesired impacts. Containment measures may also be required by law or marketplace constraints, regardless of risks or benefits. We discuss: (1) the context for when genetic containment or mitigation systems may be needed; (2) technology approaches and mechanisms; (3) the state of knowledge on genes/genomics of sexual reproduction in forest trees; (4) stability of transgene expression during vegetative growth; (5) simulation studies to define the level of containment needed; and (6) needed research to deliver effective containment technologies. We illustrate progress with several examples from our research on recombinant DNA modified poplars. Our simulations show that even partial sterility can provide very substantial reductions in gene flow into wild trees. We conclude that it is impossible to define the most effective containment approaches, nor their reliability, based on current genomic knowledge and technological tools. Additional genomic and technological studies of a wide variety of options are needed. Studies in field environments are essential to provide data relevant to ecological analysis and regulatory decisions and need to be carried out in phylogenetically diverse representatives of the economically most important taxa of forest trees.

Burdon, R. D. (1999). "Risk-management issues for genetically engineered forest trees." N Z J For Sci 29: 375-390.

Burgio, G., A. Lanzoni, et al. (2007). "Evaluation of Bt-toxin uptake by the non-target herbivore, Myzus persicae (Hemiptera: Aphididae), feeding on transgenic oilseed rape." Bull Entomol Res 97(2): 211-215.

As consequence of the concern about the biosafety of genetically modified plants, biological and ecological studies are considered crucial for environmental risk assessment. Laboratory experiments were carried out in order to evaluate the transfer of the Cry1Ac Bt-toxin from a transgenic Bt-oilseed rape to a non-target pest, Myzus persicae Sulzer. Cry1Ac protein levels in plants and aphids were determined using a double sandwich enzyme-linked immunosorbent assay. Phloem sap from (Bt+) and (Bt-) oilseed rape plants was collected from leaves using a standard method of extraction in an EDTA buffer. Bt-toxin was present in phloem sap, with a mean concentration of 2.7 +/- 1.46 ppb, corresponding to a 24-fold lower level than in oilseed rape leaves. Toxin was also detected in aphid samples, with a mean concentration in the positive samples of 2.0 +/- 0.8 ppb. The evidence that Bt-toxin remains in herbivores, in this case an aphid, could be useful to clarify functional aspects linked to possible consequences of Bt-crops on food chains involving herbivore-natural enemy trophic systems. Further studies are needed in order to improve the knowledge on the functional aspects linked to the transfer of the Cry1Ac Bt-toxin from GM-oilseed rape to aphids and their possible consequence.

Burke, J. M., K. A. Gardner, et al. (2002). "The potential for gene flow between cultivated and wild sunflower (Helianthus annuus) in the United States." American Journal of Botany 89(9): 1550-1552.

The transfer of genes from crop plants to their wild relatives via hybridization has emerged as one of the primary risks associated with the commercialization of genetically engineered crops. Although previous studies have revealed relatively high levels of hybridization when crop plants come into contact with their wild relatives, the frequency of such contact across the range of cultivation of any crop taxon is unknown. Here we report the results of a multi-year, range-wide survey of the potential for reproductive contact between cultivated and common sunflower (Helianthus annuus). The results of this work indicate that the opportunity for crop-wild hybridization exists throughout the range of sunflower cultivation. Approximately two-thirds of all cultivated fields occurred in close proximity to, and flowered coincidentally with, common sunflower populations. In these populations, the phenological overlap was extensive, with 52-96% of all wilds flowering coincidentally with the adjacent cultivar field. Moreover, there was morphological evidence of hybridization in 10-33% of the populations surveyed within a given year. These findings indicate that crop-wild hybridization is likely across the range of sunflower cultivation in the USA.

Burke, J. M. and L. H. Rieseberg (2003). "Fitness effects of transgenic disease resistance in sunflowers." Science 300(5623): 1250-1250.

Burns, M. J., K. J. Edwards, et al. (2001). "Development of simple sequence repeat (SSR) markers for the assessment of gene flow and genetic diversity in pigeonpea (Cajanus cajan)." Molecular Ecology Notes 1(4): 283-285.

Pigeonpea (Cajanus cajan) is an important subsistence crop in India where traditional landraces and improved hybrids are grown alongside each other. Gene flow may result in genetic erosion of these landraces and their wild relatives, whilst transgene escape from future genetically engineered varieties is another potential hazard. To assess the impact of these factors gene flow needs to be measured. A set of 10 simple sequence repeat markers have been developed, which exhibit polymorphism across a range of pigeonpea varieties. Use of these markers also offers an efficient system for the assessment of genetic diversity within populations of pigeonpea.

Busov, V., R. Meilan, et al. (2006). "Transgenic modification of gai or rgl1 causes dwarfing and alters gibberellins, root growth, and metabolite profiles in Populus." Planta 224(2): 288-299.

In Arabidopsis and other plants, gibberellin (GA)-regulated responses are mediated by proteins including GAI, RGA and RGL1-3 that contain a functional DELLA domain. Through transgenic modification, we found that DELLA-less versions of GAI (gai) and RGL1 (rgl1) in a Populus tree have profound, dominant effects on phenotype, producing pleiotropic changes in morphology and metabolic profiles. Shoots were dwarfed, likely via constitutive repression of GA-induced elongation, whereas root growth was promoted two- to threefold in vitro. Applied GA(3 )inhibited adventitious root production in wild-type poplar, but gai/rgl1 poplars were unaffected by the inhibition. The concentrations of bioactive GA(1) and GA(4) in leaves of gai- and rgl1-expressing plants increased 12- to 64-fold, while the C(19) precursors of GA(1) (GA(53), GA(44) and GA(19)) decreased three- to ninefold, consistent with feedback regulation of GA 20-oxidase in the transgenic plants. The transgenic modifications elicited significant metabolic changes. In roots, metabolic profiling suggested increased respiration as a possible mechanism of the increased root growth. In leaves, we found metabolite changes suggesting reduced carbon flux through the lignin biosynthetic pathway and a shift towards allocation of secondary storage and defense metabolites, including various phenols, phenolic glucosides, and phenolic acid conjugates.

Butler, S. J., J. A. Vickery, et al. (2007). "Farmland biodiversity and the footprint of agriculture." Science 315(5810): 381-384.

Sustainable development requires the reconciliation of demands for biodiversity conservation and increased agricultural production. Assessing the impact of novel farming practices on biodiversity and ecosystem services is fundamental to this process. Using farmland birds as a model system, we present a generic risk assessment framework that accurately predicts each species' current conservation status and population growth rate associated with past changes in agriculture. We demonstrate its value by assessing the potential impact on biodiversity of two controversial land uses, genetically modified herbicide-tolerant crops and agri-environment schemes. This framework can be used to guide policy and land management decisions and to assess progress toward sustainability targets.

Byrne, P. F. (2005). "Safety and Public Acceptance of Transgenic Products." Crop Sci 46(1): 113-117.

Public acceptance of transgenic (genetically engineered, GE) products is influenced by the perception of direct or indirect risks and benefits and the credibility of regulatory agencies that evaluate food and environmental safety. In North America acceptance of GE foods is holding steady, while knowledge about them remains low. Development of transgenic foods with improved nutritional properties or other quality factors will likely be better received than products that primarily benefit the grower or developer of the product. There is continuing unease about biopharming and the association, by some members of the public, of GE crops with corporate agriculture. Several recent reports have reviewed the U.S. regulatory system for transgenic crops and called for a more coordinated and transparent process that allows for greater public participation. For society to benefit from GE crops, we must move away from the polarized positions that have defined the transgenic debate in the past, to positions of mutual respect that allow a rational discussion of the technology's merits and risks.

Campbell, L. G., A. A. Snow, et al. (2006). "Weed evolution after crop gene introgression: greater survival and fecundity of hybrids in a new environment." Ecology Letters 9(11): 1198-1209.

Crop-wild hybridization may produce offspring with lower fitness than their wild parents due to deleterious crop traits and outbreeding depression. Over time, however, selection for improved fitness could lead to greater invasiveness of hybrid taxa. To examine evolutionary change in crop-wild hybrids, we established four wild (Raphanus raphanistrum) and four hybrid radish populations (R. raphanistrum x Raphanus sativus) in Michigan (MI), USA. Hybrid and wild populations had similar growth rates over four generations, and pollen fertility of hybrids improved. We then measured hybrid and wild fitness components in two common garden sites within the geographical range of wild radish [MI and California (CA)]. Advanced generation hybrids had slightly lower lifetime fecundity than wild plants in MI but exhibited c. 270% greater lifetime fecundity and c. 22% greater survival than wild plants in CA. Our results support the hypothesis that crop-wild hybridization may create genotypes with the potential to displace parental taxa in new environments.

Campbell, M. M., A. M. Brunner, et al. (2003). "Forestry's fertile crescent: the application of biotechnology to forest trees." Plant Biotechnol J 1(3): 141-154.

Relative to crop plants, the domestication of forest trees is still in its infancy. For example, the domestication of many crop plants was initiated some 10 000 years ago in the so-called 'Fertile Crescent' of the Middle East. By contrast, the domestication of forest trees for the purposes of producing more fibre began in earnest in the last half century. The application of biotechnology to forest trees offers a great potential to hasten the pace of tree improvement for desirable end uses. This review outlines some of the progress that has been made in the application of biotechnology to forest trees, and considers the prospects for biotechnologically based tree improvement in the future.

Candolfi, M. P., K. Brown, et al. (2004). "A faunistic approach to assess potential side-effects of genetically modified Bt-corn on non-target arthropods under field conditions." Biocontrol Science and Technology 14(2): 129-170.

Cantamutto, M. and M. Poverene (2007). "Genetically modified sunflower release: Opportunities and risks." Field Crops Research 101(2): 133-144.

Sunflower (Helianthus annuus L.) is a crop native to North America for which there are no genetically modified commercial varieties. Some of the transgenic traits incorporated in other crops have already been subjected to research and experimentation in sunflower. Several new traits have also been noted, with the most relevant of these being the aim to increase latex production. GM sunflower release would modify crop management through improved mineral nutrition, weed control, insect and disease resistance, and product quality. In this research, the traits investigated were reviewed and analyzed in connection with main crop constraints. These characters could potentially influence agro-ecosystem components and produce a significant environmental impact. In regions where sunflower coexists with wild relatives this situation could affect germplasm resources, with this being especially important at the centre of origin and where Helianthus populations established in Africa, Asia, and Europe. (c) 2006 Elsevier B.V. All rights reserved.

Cantani, A. (2006). "Benefits and concerns associated with biotechnology-derived foods: can additional research reduce children health risks?" Eur Rev Med Pharmacol Sci 10(4): 197-206.

The development of techniques devised for the genetic manipulation of foods poses new risks for children with food allergy (FA). The introduction of foreign allergenic proteins from different foods into previously tolerated foods may trigger allergic reactions, often complicating with anaphylactic shock in a subset of allergic babies. Children with FA, even if subjected to preventative diets, always challenge the risk of developing allergic manifestations after unintentional intake of a non tolerated food in restaurant settings, with relatives or schoolmates, etc, where product labelling is necessarily lacking. The introduction of potentially allergenic proteins into foods generally considered safe for allergic children can be done deliberately, by either substantially altering the food ingredients, or by genetic manipulation which change the composition or transfer allergens, or unintentionally by quality-control failures, due to contaminations in the production process, or to genetic mismanipulation. There is a controversy between multinationals often favored by governments and consumer association resistance, thus an equidistant analysis poses some unprecedented impediments. The importance of FA and the potential of transgenic plants to bring food allergens into the food supply should not be disregarded. The expression in soybeans of a Brazil nut protein resulted in a food allergen expressed in widely used infant formulas, so paving the way to an often reported multinational debacle. Genetic engineering poses innovative ethical and social concerns, as well as serious challenges to the environment, human health, animal welfare, and the future of agriculture. In this paper will be emphasized practical concepts more crucial for pediatricians.

CAST (2004). Biotechnology-derived, perennial turf and forage grasses: Criteria for evaluation. Ames, Iowa: 94.

Castaldini, M., A. Turrini, et al. (2005). "Impact of Bt corn on rhizospheric and on beneficial mycorrhizal symbiosis and soil eubacterial communities iosis in experimental microcosms." Applied and Environmental Microbiology 71(11): 6719-6729.

A polyphasic approach has been developed to gain knowledge of suitable key indicators for the evaluation of environmental impact of genetically modified Bt 11 and Bt 176 corn lines on soil ecosystems. We assessed the effects of Bt corn (which constitutively expresses the insecticidal toxin from Bacillus thuringiensis, encoded by the truncated Cry1Ab gene) and non-Bt corn plants and their residues on rhizospheric and bulk soil eubacterial communities by means of denaturing gradient gel electrophoresis analyses of 16S rRNA genes, on the nontarget mycorrhizal symbiont Glomus mosseae, and on soil respiration. Microcosm experiments showed differences in rhizospheric eubacterial communities associated with the three corn lines and a significantly lower level of mycorrhizal colonization in Bt 176 corn roots. In greenhouse experiments, differences between Bt and non-Bt corn plants were detected in rhizospheric eubacterial communities (both total and active), in culturable rhizospheric heterotrophic bacteria, and in mycorrhizal colonization. Plant residues of transgenic plants, plowed under at harvest and kept mixed with soil for up to 4 months, affected soil respiration, bacterial communities, and mycorrhizal establishment by indigenous endophytes. The multimodal approach utilized in our work may be applied in long-term field studies aimed at monitoring the real hazard of genetically modified crops and their residues on nontarget soil microbial communities.

Castaldini, M., A. Turrini, et al. (2005). "Impact of Bt corn on rhizospheric and soil eubacterial communities and on beneficial mycorrhizal symbiosis in experimental microcosms." Appl Environ Microbiol 71(11): 6719-6729.

A polyphasic approach has been developed to gain knowledge of suitable key indicators for the evaluation of environmental impact of genetically modified Bt 11 and Bt 176 corn lines on soil ecosystems. We assessed the effects of Bt corn (which constitutively expresses the insecticidal toxin from Bacillus thuringiensis, encoded by the truncated Cry1Ab gene) and non-Bt corn plants and their residues on rhizospheric and bulk soil eubacterial communities by means of denaturing gradient gel electrophoresis analyses of 16S rRNA genes, on the nontarget mycorrhizal symbiont Glomus mosseae, and on soil respiration. Microcosm experiments showed differences in rhizospheric eubacterial communities associated with the three corn lines and a significantly lower level of mycorrhizal colonization in Bt 176 corn roots. In greenhouse experiments, differences between Bt and non-Bt corn plants were detected in rhizospheric eubacterial communities (both total and active), in culturable rhizospheric heterotrophic bacteria, and in mycorrhizal colonization. Plant residues of transgenic plants, plowed under at harvest and kept mixed with soil for up to 4 months, affected soil respiration, bacterial communities, and mycorrhizal establishment by indigenous endophytes. The multimodal approach utilized in our work may be applied in long-term field studies aimed at monitoring the real hazard of genetically modified crops and their residues on nontarget soil microbial communities.

Cattaneo, M. G., C. Yafuso, et al. (2006). "Farm-scale evaluation of the impacts of transgenic cotton on biodiversity, pesticide use, and yield." Proc Natl Acad Sci U S A 103(20): 7571-7576.

Higher yields and reduced pesticide impacts are needed to mitigate the effects of agricultural intensification. A 2-year farm-scale evaluation of 81 commercial fields in Arizona show that use of transgenic Bacillus thuringiensis (Bt) cotton reduced insecticide use, whereas transgenic cotton with Bt protein and herbicide resistance (BtHr) did not affect herbicide use. Transgenic cotton had higher yield than nontransgenic cotton for any given number of insecticide applications. However, nontransgenic, Bt and BtHr cotton had similar yields overall, largely because higher insecticide use with nontransgenic cotton improved control of key pests. Unlike Bt and BtHr cotton, insecticides reduced the diversity of nontarget insects. Several other agronomic and ecological factors also affected biodiversity. Nevertheless, pairwise comparisons of diversity of nontarget insects in cotton fields with diversity in adjacent noncultivated sites revealed similar effects of cultivation of transgenic and nontransgenic cotton on biodiversity. The results indicate that impacts of agricultural intensification can be reduced when replacement of broad-spectrum insecticides by narrow-spectrum Bt crops does not reduce control of pests not affected by Bt crops.

CBD (2003). Biosafety and the environment: An introduction to the Cartagena Protocol on Biosafety.

Celis, C., M. Scurrah, et al. (2004). "Environmental biosafety and transgenic potato in a centre of diversity for this crop." Nature 432(7014): 222-225.

The Nuffield Council on Bioethics suggests that introgression of genetic material into related species in centres of crop biodiversity is an insufficient justification to bar the use of genetically modified crops in the developing world. They consider that a precautionary approach to forgo the possible benefits invokes the fallacy of thinking that doing nothing is itself without risk to the poor. Here we report findings relevant to this and other aspects of environmental biosafety for genetically modified potato in its main centre of biodiversity, the central Andes. We studied genetically modified potato clones that provide resistance to nematodes, principal pests of Andean potato crops. We show that there is no harm to many non-target organisms, but gene flow occurs to wild relatives growing near potato crops. If stable introgression were to result, the fitness of these wild species could be altered. We therefore transformed the male sterile cultivar Revolucion to provide a genetically modified nematode-resistant potato to evaluate the benefits that this provides until the possibility of stable introgression to wild relatives is determined. Thus, scientific progress is possible without compromise to the precautionary principle.

Cerdeira, A. L. and S. O. Duke (2006). "The current status and environmental impacts of glyphosate-resistant crops: a review." J Environ Qual 35(5): 1633-1658.

Glyphosate [N-(phosphonomethyl) glycine]-resistant crops (GRCs), canola (Brassica napus L.), cotton (Gossypium hirsutum L.), maize (Zea mays L.), and soybean [Glycine max (L.) Merr.] have been commercialized and grown extensively in the Western Hemisphere and, to a lesser extent, elsewhere. Glyphosate-resistant cotton and soybean have become dominant in those countries where their planting is permitted. Effects of glyphosate on contamination of soil, water, and air are minimal, compared to some of the herbicides that they replace. No risks have been found with food or feed safety or nutritional value in products from currently available GRCs. Glyphosate-resistant crops have promoted the adoption of reduced- or no-tillage agriculture in the USA and Argentina, providing a substantial environmental benefit. Weed species in GRC fields have shifted to those that can more successfully withstand glyphosate and to those that avoid the time of its application. Three weed species have evolved resistance to glyphosate in GRCs. Glyphosate-resistant crops have greater potential to become problems as volunteer crops than do conventional crops. Glyphosate resistance transgenes have been found in fields of canola that are supposed to be non-transgenic. Under some circumstances, the largest risk of GRCs may be transgene flow (introgression) from GRCs to related species that might become problems in natural ecosystems. Glyphosate resistance transgenes themselves are highly unlikely to be a risk in wild plant populations, but when linked to transgenes that may impart fitness benefits outside of agriculture (e.g., insect resistance), natural ecosystems could be affected. The development and use of failsafe introgression barriers in crops with such linked genes is needed.

Cerdeira, A. L., D. L. Gazziero, et al. (2007). "Review of potential environmental impacts of transgenic glyphosate-resistant soybean in Brazil." J Environ Sci Health B 42(5): 539-549.

Transgenic glyphosate-resistant soybeans (GRS) have been commercialized and grown extensively in the Western Hemisphere, including Brazil. Worldwide, several studies have shown that previous and potential effects of glyphosate on contamination of soil, water, and air are minimal, compared to those caused by the herbicides that they replace when GRS are adopted. In the USA and Argentina, the advent of glyphosate-resistant soybeans resulted in a significant shift to reduced- and no-tillage practices, thereby significantly reducing environmental degradation by agriculture. Similar shifts in tillage practiced with GRS might be expected in Brazil. Transgenes encoding glyphosate resistance in soybeans are highly unlikely to be a risk to wild plant species in Brazil. Soybean is almost completely self-pollinated and is a non-native species in Brazil, without wild relatives, making introgression of transgenes from GRS virtually impossible. Probably the highest agricultural risk in adopting GRS in Brazil is related to weed resistance. Weed species in GRS fields have shifted in Brazil to those that can more successfully withstand glyphosate or to those that avoid the time of its application. These include Chamaesyce hirta (erva-de-Santa-Luzia), Commelina benghalensis (trapoeraba), Spermacoce latifolia (erva-quente), Richardia brasiliensis (poaia-branca), and Ipomoea spp. (corda-de-viola). Four weed species, Conyza bonariensis, Conyza Canadensis (buva), Lolium multiflorum (azevem), and Euphorbia heterophylla (amendoim bravo), have evolved resistance to glyphosate in GRS in Brazil and have great potential to become problems.

Chapman, M. A. and J. M. Burke (2006). "Letting the gene out of the bottle: the population genetics of genetically modified crops." New Phytol 170(3): 429-443.

Genetically modified (GM) plants are rapidly becoming a common feature of modern agriculture. This transition to engineered crops has been driven by a variety of potential benefits, both economic and ecological. The increase in the use of GM crops has, however, been accompanied by growing concerns regarding their potential impact on the environment. Here, we focus on the escape of transgenes from cultivation via crop x wild hybridization. We begin by reviewing the literature on natural hybridization, with particular reference to gene flow between crop plants and their wild relatives. We further show that natural selection, and not the overall rate of gene flow, is the most important factor governing the spread of favorable alleles. Hence, much of this review focuses on the likely effects of transgenes once they escape. Finally, we consider strategies for transgene containment.

Chassy, B., C. Carter, et al. (2003). "UK field-scale evaluations answer wrong questions." Nat Biotechnol 21(12): 1429-1430.

Chevre, A. M., F. Eber, et al. (1998). "Characterization of backcross generations obtained under field conditions from oilseed rape wild radish F-1 interspecific hybrids: an assessment of transgene dispersal." Theoretical and Applied Genetics 97(1-2): 90-98.

Gene flow from glufosinate-resistant transgenic oilseed rape to wild radish was studied over two backcross generations. Under field conditions,seed production from oilseed rape-wild radish F-1 hybrids due to pollination by wild radish was always low: on average 0.12 and 0.78 seeds per 100 flowers and per plant, respectively. The cytogenetics of the resulting "BC1" plants can be explained in the main by three different genomic constitutions: either ACRrRr, 2n = 37, ACRr, 2n = 28 (the same chromosome number as the mother plant), or by the amphidiploid AACCRrRr, 2n = 56. The probability of gene exchange through chromosome pairing was high only in plants with Zn = 28 or 37 chromosomes. Due to the viability of unreduced or partially reduced female gametes, most of the "BC1" plants (81.9%) were Basta resistant whereas the analysis of oilseed rape specific loci indicated that their transmission varied with the locus. In spite of low male fertility (8.7%), an improvement of the female fertility over the F-1 hybrids was observed with an average production of 1.4 and 11 seeds per 100 flowers and per plant, respectively. At the following "BC2" generation, the bar gene transmission (57.2% of Basta-resistant plants) decreased as did the chromosome number, with a majority of plants having between 24 and 27 chromosomes, with 10.5% similar to wild radish (2n = 18). The lower the chromosome number, the better the fertility of the "BC2" plants. On average, 7.9 and 229.3 seeds per 100 flowers and per plant were produced. Gene-flow assessment is discussed based on these data.

Chilcutt, C. F. and B. E. Tabashnik (2004). "Contamination of refuges by Bacillus thuringiensis toxin genes from transgenic maize." Proc Natl Acad Sci U S A 101(20): 7526-7529.

Transgenic crops producing insecticidal toxins from Bacillus thuringiensis (Bt) are widely used to control pests, but their benefits will be lost if pests evolve resistance. The mandated high-dose/refuge strategy for delaying pest resistance requires planting refuges of toxin-free crops near Bt crops to promote survival of susceptible pests. We report that pollen-mediated gene flow up to 31 m from Bt maize caused low to moderate Bt toxin levels in kernels of non-Bt maize refuge plants. Immunoassays of non-Bt maize sampled from the field showed that the mean concentration of Bt toxin Cry1Ab in kernels and the percentage of kernels with Cry1Ab decreased with distance from Bt maize. The highest Bt toxin concentration in pooled kernels of non-Bt maize plants was 45% of the mean concentration in kernels from adjacent Bt maize plants. Most previous work on gene flow from transgenic crops has emphasized potential effects of transgene movement on wild relatives of crops, landraces, and organic plantings, whereas implications for pest resistance have been largely ignored. Variable Bt toxin production in seeds of refuge plants undermines the high-dose/refuge strategy and could accelerate pest resistance to Bt crops. Thus, guidelines should be revised to reduce gene flow between Bt crops and refuge plants.

Clark, B. W., T. A. Phillips, et al. (2005). "Environmental fate and effects of Bacillus thuringiensis (Bt) proteins from transgenic crops: a review." Journal of Agricultural and Food Chemistry 53(12): 4643-4653.

This paper reviews the scientific literature addressing the environmental fate and nontarget effects of the Cry protein toxins from Bacillus thuringiensis (Bt), specifically resulting from their expression in transgenic crops. Published literature on analytical methodologies for the detection and quantification of the Cry proteins in environmental matrices is also reviewed, with discussion of the adequacy of the techniques for determining the persistence and mobility of the Bt proteins. In general, assessment of the nontarget effects of Bt protein toxins indicates that there is a low level of hazard to most groups of nontarget organisms, although some investigations are of limited ecological relevance. Some published reports on the persistence of the proteins in soil show short half-lives, whereas others show low-level residues lasting for many months. Improvements in analytical methods will allow a more complete understanding of the fate and significance of Bt proteins in the environment.

Clark, E. A. (2006). "Environmental risks of genetic engineering." Euphytica 148(1-2): 47-60.

Before release into commerce, genetically engineered organisms are first assessed for possible risks, including risks to the environment. The present paper first identifies the environmental risks recognized by regulators, and reviews the parameters considered predictive of risk. Recent field-scale studies suggest opportunities for improvement of the environmental risk assessment process. Risks unique to genetically engineered crops - if any - could pertain to the specific traits chosen for commercialization and to unintended trait expression caused by the process of transgene insertion itself. Both the standard against which to compare genetically engineered traits and the scale of exposure need to be considered when assessing environmental impact. Evidence of environmental risk in the recognized areas of weediness on agricultural land, invasiveness of unmanaged systems, and non-target impacts from Bacillus thuringiensis (Bt) maize is presented. Targeted, statistically sound, rigorously conducted, multi-trophic studies analogous to the Field Scale Evaluation trials recently completed in the UK are needed to clarify the many questions which remain unanswered.

Clark, E. A. and H. Lehman (2001). "Assessment of GM crops in commercial agriculture." Journal of agricultural & environmental ethics 14: 3-28.

Clark, S. J., P. Rothery, et al. (2006). "Farm Scale Evaluations of spring-sown genetically modified herbicide-tolerant crops: a statistical assessment." Proc Biol Sci 273(1583): 237-243.

Primary results from the Farm Scale Evaluations (FSEs) of spring-sown genetically modified herbicide-tolerant crops were published in 2003. We provide a statistical assessment of the results for count data, addressing issues of sample size (n), efficiency, power, statistical significance, variability and model selection. Treatment effects were consistent between rare and abundant species. Coefficients of variation averaged 73% but varied widely. High variability in vegetation indicators was usually offset by large n and treatment effects, whilst invertebrate indicators often had smaller n and lower variability; overall, achieved power was broadly consistent across indicators. Inferences about treatment effects were robust to model misspecification, justifying the statistical model adopted. As expected, increases in n would improve detectability of effects whilst, for example, halving n would have resulted in a loss of significant results of about the same order. 40% of the 531 published analyses had greater than 80% power to detect a 1.5-fold effect; reducing n by one-third would most likely halve the number of analyses meeting this criterion. Overall, the data collected vindicated the initial statistical power analysis and the planned replication. The FSEs provide a valuable database of variability and estimates of power under various sample size scenarios to aid planning of more efficient future studies.

Cleveland, D. A. and D. Soleri (2005). "Rethinking the risk management process for genetically engineered crop varieties in small-scale, traditionally based agriculture." Ecology and Society 10(1).

Proponents of genetically engineered (GE) crops often assume that the risk management used in the industrial world is appropriate for small-scale, traditionally based agriculture in the Third World. Opponents of GE crops often assume that risk management is inappropriate for the Third World, because it is inherently biased in favor of the industrial world. We examine both of these assumptions, by rethinking risk management for GE crops and transgenes, using the example of maize transgene flow from the U. S. to Mexico. Risk management for the Third World is a necessary first step of a broader benefit-cost analysis of GE crops, which would include comparisons with existing varieties and with alternative varieties such as transgenic farmer varieties and organic varieties. Our goal is to use existing information on GE crops and on the social and biological characteristics of Third World agriculture to identify key processes that need to be considered in risk management, and the additional research required to adequately understand them. The four main steps in risk management are hazard identification, risk analysis ( exposure x harm), risk evaluation, and risk treatment. We use informal event trees to identify possible exposure to GE crops and transgenes, and resulting biological and social harm; give examples of farmers' ability to evaluate social harm; and discuss the possibilities for risk treatment. We conclude that risk management is relevant for Third World agriculture, but needs to be based on the unique biological and social characteristics of small-scale, traditionally based agriculture, including the knowledge and values of Third World farmers and consumers.

Cleveland, D. A., D. Soleri, et al. (2005). "Detecting (trans)gene flow to landraces in centers of crop origin: lessons from the case of maize in Mexico." Environ Biosafety Res 4(4): 197-208; discussion 209-115.

There is much discussion of the probability of transgene flow from transgenic crop varieties to landraces and wild relatives in centers of origin or diversity, and its genetic, ecological, and social consequences. Without costly research on the variables determining gene flow, research on transgene frequencies in landrace (or wild relative) populations can be valuable for understanding transgene flow and its effects. Minimal research requirements include (1) understanding how farmer practices and seed systems affect landrace populations, (2) sampling to optimize Ne/n (effective/census population size), (3) minimizing variance at all levels sampled, and (4) using Ne to calculate binomial probabilities for transgene frequencies. A key case is maize in Mexico. Two peer-reviewed papers, based on landrace samples from the Sierra Juarez region of Oaxaca, Mexico, reached seemingly conflicting conclusions: transgenes are present (Quist and Chapela, 2001, Nature 414: 541-543; 2002, Nature 416: 602) or "detectable transgenes" are absent (Ortiz-Garcia et al., 2005, Proc. Natl. Acad. Sci. USA 102: 12338-12343 and 18242). We analyzed these papers using information on Oaxacan maize seed systems and estimates of Ne. We conclude that if Quist and Chapela's results showing presence are accepted, Ortiz-Garcia et al.'s conclusions of no evidence of transgenes at detectable levels or for their introgression into maize landraces in the Sierra de Juarez of Oaxaca are not scientifically justified. This is because their samples are not representative, and their statistical analysis is inconclusive due to using n instead of Ne. Using estimates of Ne based on Ortiz-Garcia et al.'s n, we estimate that transgenes could be present in maize landraces in the Sierra Juarez region at frequencies of approximately 1-4%, and are more likely to be present in the 90% of Oaxacan landrace area that is not mountainous. Thus, we have no scientific evidence of maize transgene presence or absence in recent years in Mexico, Oaxaca State, or the Sierra Juarez region.

Cockburn, A. (2002). "Assuring the safety of genetically modified (GM) foods: the importance of an holistic, integrative approach." J Biotechnol 98(1): 79-106.

Genes change continuously by natural mutation and recombination enabling man to select and breed crops having the most desirable traits such as yield or flavour. Genetic modification (GM) is a recent development which allows specific genes to be identified, isolated, copied and inserted into other plants with a high level of specificity. The food safety considerations for GM crops are basically the same as those arising from conventionally bred crops, very few of which have been subject to any testing yet are generally regarded as being safe to eat. In contrast a rigorous safety testing paradigm has been developed for GM crops, which utilises a systematic, stepwise and holistic approach. The resultant science based process, focuses on a classical evaluation of the toxic potential of the introduced novel trait and the wholesomeness of the transformed crop. In addition, detailed consideration is given to the history and safe use of the parent crop as well as that of the gene donor. The overall safety evaluation is conducted under the concept known as substantial equivalence which is enshrined in all international crop biotechnology guidelines. This provides the framework for a comparative approach to identify the similarities and differences between the GM product and its comparator which has a known history of safe use. By building a detailed profile on each step in the transformation process, from parent to new crop, and by thoroughly evaluating the significance from a safety perspective, of any differences that may be detected, a very comprehensive matrix of information is constructed which enables the conclusion as to whether the GM crop, derived food or feed is as safe as its traditional counterpart. Using this approach in the evaluation of more than 50 GM crops which have been approved worldwide, the conclusion has been that foods and feeds derived from genetically modified crops are as safe and nutritious as those derived from traditional crops. The lack of any adverse effects resulting from the production and consumption of GM crops grown on more than 300 million cumulative acres over the last 5 years supports these safety conclusions.

Colbach, N., C. Clermont-Dauphin, et al. (2001). "GENESYS: a model of the influence of cropping system on gene escape from herbicide tolerant rapeseed crops to rape volunteers - II. Genetic exchanges among volunteer and cropped populations in a small region." Agriculture Ecosystems & Environment 83(3): 255-270.

The aim of the model GENESYS is to rank cropping systems according to their risk of gene escape from genetically modified. herbicide tolerant winter oilseed rape cultivars to rapeseed volunteers. The model integrates the effects of crop succession and crop management at the level of a region. The first part of the model presented by Colbach et al. [Colbach, N., Clermont-Dauphin, C., Meynard, J.M., 2001. GENESYS: a model of the influence of cropping system on gene escape from herbicide tolerant rapeseed crops to rape volunteers. I. Temporal evolution of a population of rapeseed volunteers in a field. Agric. Ecosyst. Environ.. in press], describes the temporal evolution of rapeseed volunteers in a field. In this paper, the temporal sub-model was extended to include the evolution of genotype proportions with time and the effect of genotype on herbicide efficacy, on seed and pollen production. The spatial dimension was introduced by modelling demographic and genetic evolution of rapeseed volunteers in all the plots of a region, whether they are cropped fields or uncultivated field margins and waysides. Each year, pollen and seed are exchanged between plots and the importance of these exchanges depends on plot areas and distances. and, in the case of pollen, on flowering dates. (C) 2001 Elsevier Science B.V. All rights reserved.

Colbach, N., J. M. Meynard, et al. (2000). "GeneSys-Colza: a model for the medium-term and long-term effects of cultivation systems on the flows of genes between colza fields and new growth in a given agricultural area." Ocl-Oleagineux Corps Gras Lipides 7(4): 329-340.

The aim of the model is to evaluate the influence of cropping systems on transgene escape from rapeseed crops to rapeseed volunteers in time and space. The model input variables are the regional field pattern, crop succession and cultivation techniques. The main output variables are, for each year and plot, the number of individuals per m(2) and the genotype proportions of the adult rapeseed plants, the newly produced seeds and the seedbank. The model comprises an annual life- cycle for volunteer and cropped rapeseed plants simulated for each plot and year; the relationships between the various life- stages depend on crop type and management. Pollen and grain exchanges between plots depend on distance between plots and cropping system. With the help of the simulations performed with the model, it is possible to identify low-gene-flow cropping systems or the minimum distance between rape plots to avoid contamination of the harvest product, to estimate the consequences if one farmer does not manage his rope volunteers correctly etc.

Conner, A. J., T. R. Glare, et al. (2003). "The release of genetically modified crops into the environment. Part II. Overview of ecological risk assessment." Plant J 33(1): 19-46.

Despite numerous future promises, there is a multitude of concerns about the impact of GM crops on the environment. Key issues in the environmental assessment of GM crops are putative invasiveness, vertical or horizontal gene flow, other ecological impacts, effects on biodiversity and the impact of presence of GM material in other products. These are all highly interdisciplinary and complex issues. A crucial component for a proper assessment is defining the appropriate baseline for comparison and decision. For GM crops, the best and most appropriately defined reference point is the impact of plants developed by traditional breeding. The latter is an integral and accepted part of agriculture. In many instances, the putative impacts identified for GM crops are very similar to the impacts of new cultivars derived from traditional breeding. When assessing GM crops relative to existing cultivars, the increased knowledge base underpinning the development of GM crops will provide greater confidence in the assurances plant science can give on the risks of releasing such crops.

Conner, A. J. and J. M. Jacobs (2000). "Food risks from transgenic crops in perspective." Nutrition 16(7-8): 709-711.

Couvet, D. (2005). "Leave GM analysis to the relevant scientists." Nature 436(7049): 328.

Cowgill, S. E. and H. J. Atkinson (2003). "A sequential approach to risk assessment of transgenic plants expressing protease inhibitors: effects on nontarget herbivorous insects." Transgenic Research 12(4): 439-449.

Protease inhibitors expressed in transgenic plants can provide enhanced levels of resistance to important pest species. A sequential approach for testing the effects of protease inhibitor-expressing crops on nontarget herbivorous insects has been developed. The approach consists of five tiers. The first two tiers comprise the selection phase. In tier one, field surveys are used to characterise the nontarget invertebrate fauna of a crop. In tier 2, histochemical assays are used to identify the subset of herbivores with a particular class of digestive proteolytic enzymes. In the assessment phase a combination of laboratory 'worst-case scenario' studies (tier 3) and controlled environment or small-scale field trials (tier 4) are used to evaluate the impact of the protease inhibitor-expressing plants on the selected nontarget species. In the final tier, field trials are used to compare the relative effect of transgenic plants and current management practices, such as pesticide use, on selected species. The first four tiers of the approach are described using potatoes expressing cystatins, a family of cysteine proteinase inhibitors, as an example. Although the plants have enhanced levels of resistance to potato cyst nematodes (PCN), Globodera pallida and Globodera rostochiensis, the results establish that they have negligible impact on the nontarget herbivorous insect, Eupteryx aurata.

Cowgill, S. E., R. D. Bardgett, et al. (2002). "The effect of transgenic nematode resistance on non-target organisms in the potato rhizosphere." Journal of Applied Ecology 39(6): 915-923.

1. Plant-parasitic nematodes are important pests of agriculture and transgenic plants with potential for nematode control are currently being developed. The expression of cysteine proteinase inhibitors (cystatins) in potato confers partial resistance to potato-cyst nematode (PCN). Here, we used field studies to test for effects of cystatin-expressing potato on non-target soil organisms. 2. Microbial community structure, soil microarthropods and litter decomposition were studied during two growing seasons. In the second year, nematode control options of cystatin-expressing plants and an oxime carbamate nematicide application were compared for their non- target effects. 3. In the first year, the transgenic lines had no effect on the abundance, evenness or metabolic activity of the soil microbial community as determined by ester-linked phospholipid fatty acid analysis (PLFA). However, one transgenic line (D6/7) influenced the structure of the soil microbial community. PLFA suggested it favoured fungal growth relative to bacterial growth during the latter parts of the growing season. A second transgenic line (D5/13) was more effective against PCN. It reduced the abundance of the fungal fatty acid 18:2omega6 in late season, suggesting a suppression of fungal growth. 4. In the second year PLFA analysis suggested microbial abundance was reduced by 15% and 23% in the nematicide and transgenic treatments, respectively, relative to the control. Nematicidal treatment reduced the bacterial fraction of the microbial community, whereas the transgenic plants suppressed both the bacterial and fungal community components. 5. The observed changes in soil microbial community structure did not result in changes in the rate of leaf litter decomposition. 6. The transgenic lines had no significant effect on the abundance of soil microarthropods or free-living nematodes. 7. The study is the first stage of a risk assessment of the impact of transgenic nematode resistance on non-target soil organisms. It has highlighted the importance of including currently used management options when studying the effect of transgenic plants on non-target organisms. Both nematicide use and the transgenic plants affected components of the soil microbial community. However, the changes brought about by the two treatments were not sufficient to affect soil functioning, as measured by rates of litter decomposition.

Craig, W., M. Tepfer, et al. "An overview of general features of risk assessments of genetically modified crops." Euphytica.

Abstract  The intentional introduction into the environment or market of genetically modified organisms (GMOs) is nearly always governed by a framework of science-based risk assessment and risk management measures. This is usually implemented through the integration of hazard identification and characterisation of all of the elements of risk associated with a new GM crop or derived product. Typical categories of hazards arising from the introduction of transgenic crops include: possible unintended negative health effects in a susceptible subgroup of the consumer (target) population; the evolution of resistance in the targeted pest/pathogen populations when the transgene confers resistance to a pest or pathogen; non-target hazards associated directly or indirectly with the transgenic plant or transgene product outside the plant; and those associated with the integration and subsequent expression of the transgene in a different organism or species following gene flow. The consequences of likely exposure to these and other hazards are considered in this introduction to the main issues raised when evaluating the possible risks arising from the importation or cultivation of genetically modified crops.

Cranor, C. F. (2003). "How should society approach the real and potential risks posed by new technologies?" Plant Physiol 133(1): 3-9.

Crawley, M. J., R. S. Hails, et al. (1993). "Ecology of Transgenic Oilseed Rape in Natural Habitats." Nature 363(6430): 620-623.

CONCERNS about genetically engineered crop plants centre on three conjectural risks: that transgenic crop plants will become weeds of agriculture or invasive of natural habitats; that their engineered genes will be transferred by pollen to wild relatives whose hybrid offspring will then become more weedy or more invasive; or that the engineered plants will be a direct hazard to humans, domestic animals or beneficial wild organisms (toxic or allergenic, for example). Here we describe an experimental protocol for assessing the invasiveness of plants. The object is to determine whether genetic engineering for herbicide tolerance affects the likelihood of oilseed rape becoming invasive of natural habitats. By estimating the demographic parameters of transgenic and conventional oilseed rape growing in a variety of habitats and under a range of climatic conditions, we obtain a direct comparison of the ecological performance of three different genetic lines (control, kanamycin-tolerant transgenics and herbicide-tolerant transgenic lines). Despite substantial variation in seed survival, lines were less invasive and less persistent than their conventional counter arts.

Cresswell, J. E. (1994). "A Method for Quantifying the Gene Flow That Results from a Single Bumblebee Visit Using Transgenic Oilseed Rape, Brassica- Napus L Cv Westar." Transgenic Research 3(2): 134-137.

Genetically modified plants containing selectable markers offer a unique opportunity for pollination biologists to investigate some of the major, but intractable questions about paternity distributions and their causes. Here, a method is reported that uses transgenic plants to enable the quantification of the outcrossed fertilizations that result from a single pollinator visit. Gene flow mediated by worker bumblebees (Bombus terrestris) was studied among plants of oilseed rape (Brassica napus L. cv. Westar) where transgenic paternity in seeds of a non-transgenic plant was manifested as herbicide resistance. Overall, 91% of the resistant seeds resulted from the first four flowers that were visited after the bumblebee left the transgenic plant, and none was found beyond the 14th successively visited newer. The possibilities for developing the method to address various questions in pollination biology are discussed.

Cresswell, J. E., J. L. Osborne, et al. (2002). "A model of pollinator-mediated gene flow between plant populations with numerical solutions for bumblebees pollinating oilseed rape." Oikos 98(3): 375-384.

We present a model that predicts the level of gene flow mediated by animal pollinators from a source population to a sink population. The model requires specification of three elements: (1) the paternity that originates from a single flower, the paternity shadow; (2) the mean number of flowers that pollinators visit during stays in the sink population, the residence; (3) the proportion of pollinators arriving at the sink that carry pollen from the source population. Provided that pollinators visit enough flowers in the sink to exhaust the paternity shadows from the source, the general results are that gene flow is inversely proportional to the mean pollinator residence in the sink population, and is proportional to the fraction of pollinators arriving with pollen from the source. These results are used to propose explanations for two of the widely observed patterns in gene flow among plant populations. Numerical solutions to the model are derived using experimentally determined values of elements (1) and (2) that represent bumblebees, Bombus spp., visiting agricultural fields of oilseed rape, Brassica napus L. In B. napus, the paternity shadow attenuates rapidly over approximately 20 recipient flowers. Mean bumblebee residences in the fields studied varied between 490 and 720 flowers. In the absence of a direct measurement of element (3), we calculated the maximum level of bumblebee-mediated gene flow by assuming that all bees arrived at the sink saturated with pollen from extrinsic sources. In this case, the model predicts that bumblebee-mediated gene flow accounted for between 0.1% and 0.5% of the progeny in the agricultural fields studied. A likelihood analysis Of Our observations is unable to reveal convincingly the proportion of bees arriving at the sink via a source population, but the literature suggests that bumblebees have high site fidelity, which implies that bee-mediated gene flow may be substantially less than our estimated maximum. We consider the role of various factors, including wind pollination, in accounting for the differences between the model's predictions and the generally higher levels of gene flow observed in previous studies of oilseed rape.

Cummings, C. L. and H. M. Alexander (2002). "Population ecology of wild sunflowers: effects of seed density and post-dispersal vertebrate seed predators." Oecologia 130(2): 274-280.

Assessing the effects of seed density on the population dynamics of wild plant species with crop relatives will be vital in determining the potential effects of introducing traits into wild populations as a result of crop-to-wild gene flow. We examined experimental sunflower (Helianthus annuus) patches in eastern Kansas to determine the effects of seed density and predation on seedling recruitment and seed production in the next generation. High seed density treatment plots had significantly more seedlings and adult plants than did low seed density treatment plots. Overwinter vertebrate seed predator exclusion treatments resulted in increases in plant density compared to plots in which vertebrates were not excluded. Control patches (no seeds added) contained virtually no plants. Head production and estimated total seed production for a patch were not statistically different among treatments (excluding control plots). Although initial seed density and vertebrate post-dispersal seed predation do appear to have effects on seedling recruitment. neither appear to be limiting seed production of competing adult plants. Therefore, variation in seed densities (over the range examined) may have limited effects on local population dynamics. It is important to note that the choice of seed densities may affect the results obtained: the seed densities used in this study may, in retrospect. be higher than in the small roadside populations typical in eastern Kansas. yet other natural sites have much larger densities. Further. the effects of increased seed density at a local site may have other important effects such as altering metapopulation dynamics through increased long- distance dispersal or increased local seed bank size.

Cummings, C. L., H. M. Alexander, et al. (2002). "Fecundity selection in a sunflower crop-wild study: Can ecological data predict crop allele changes?" Ecological Applications 12(6): 1661-1671.

Genes that spread from transgenic crops to populations of weedy relatives can be a cause of concern if fitness-related, transgenic traits persist and enhance weed invasiveness. Studies of the prevalence of crop-specific genetic markers in wild populations can provide data on such introgression. We conducted a field experiment in eastern Kansas to measure changes in frequencies of crop-specific genetic markers in wild sunflower (Helianthus annuus). Three allozyme markers were monitored in three artificial populations that each initially consisted of 100 wild and 100 F, hybrid plants. Survival, flowering time, and average seed production per plant were quantified during the first year of the study (1997). Hybrid plants produced only 1-2% as many seeds per plant as wild plants but did not differ in survivorship. Simple selection models incorporating fecundity differences between wild and F, hybrids accurately predicted crop allele frequencies in the 1998 seedlings. We predicted that frequencies of crop alleles in 1998 would average similar to0.03 for the three populations. Crop-specific allele frequencies dropped from the initial level of 0.25 to a mean of 0.03 in the 1998 seedlings and averaged 0.05 in the next generation of seeds. Accounting for differences in flowering phenology and predispersal seed predation did not improve the accuracy of our predictions for 1998 seedlings. Our results suggest that ecological data can be useful for estimating the frequencies of crop genes following episodes of crop-wild hybridization in sunflowers. This approach can be applied to other study systems in which data on survivorship and fecundity are used to estimate a genotype's evolutionary fitness.

Dale, P. J. (2002). "The environmental impact of genetically modified (GM) crops: a review." Journal of agricultural science 138: 245-248.

Evaluating environmental impact is more complex than statistical analysis; it requires value judgements about which kinds of environmental impacts are acceptable and which are not. The new EU Directive on the release and commercialization of genetically modified (GM) crops (2001-18-EC) includes a requirement for an assessment of indirect effects on the environment of farming practices associated with the introduction of a GM crop. There is also a requirement for post-commercialization monitoring to address impacts of scale and time. Both of these additions to the regulations present challenges in deciding how environmental impacts should be measured, and in judging their acceptability. Impacts can also be socio-economic. These frequently require scientific tools to help to resolve them. The demands by some food sectors for zero GM content in crop produce is likely to prove difficult or impossible to verify by analytical procedures. It will probably be necessary to agree on levels of tolerance of the presence of GM material in "non-GM" crop produce. It is important that the future use of biotechnology in agriculture is considered in the context of a broader discussion about our vision for agriculture and the environment over the coming decades.

Dale, P. J., B. Clarke, et al. (2002). "Potential for the environmental impact of transgenic crops." Nat Biotechnol 20(6): 567-574.

In recent years, there has been increasing interest in how changes in agricultural practice associated with the introduction of particular genetically modified (GM) crops might indirectly impact the environment. There is also interest in any effects that might be associated with recombinant and novel combinations of DNA passing into the environment, and the possibility that they may be taken up by microorganisms or other live biological material. From the current state of knowledge, the impact of free DNA of transgenic origin is likely to be negligible compared with the large amount of total free DNA. We can find no compelling scientific arguments to demonstrate that GM crops are innately different from non-GM crops. The kinds of potential impacts of GM crops fall into classes familiar from the cultivation of non-GM crops (e.g., invasiveness, weediness, toxicity, or biodiversity). It is likely, however, that the novelty of some of the products of GM crop improvement will present new challenges and perhaps opportunities to manage particular crops in creative ways.

Daniell, H. (2002). "Molecular strategies for gene containment in transgenic crops." Nat Biotechnol 20(6): 581-586.

The potential of genetically modified (GM) crops to transfer foreign genes through pollen to related plant species has been cited as an environmental concern. Until more is known concerning the environmental impact of novel genes on indigenous crops and weeds, practical and regulatory considerations will likely require the adoption of gene-containment approaches for future generations of GM crops. Most molecular approaches with potential for controlling gene flow among crops and weeds have thus far focused on maternal inheritance, male sterility, and seed sterility. Several other containment strategies may also prove useful in restricting gene flow, including apomixis (vegetative propagation and asexual seed formation), cleistogamy (self-fertilization without opening of the flower), genome incompatibility, chemical induction/deletion of transgenes, fruit-specific excision of transgenes, and transgenic mitigation (transgenes that compromise fitness in the hybrid). As yet, however, no strategy has proved broadly applicable to all crop species, and a combination of approaches may prove most effective for engineering the next generation of GM crops.

Daniell, H., R. Datta, et al. (1998). "Containment of herbicide resistance through genetic engineering of the chloroplast genome." Nature Biotechnology 16(4): 345-348.

Glyphosate is a potent herbicide. It works by competitive inhibition of the enzyme 5-enol-pyruvyl shikimate-3-phosphate synthase (EPSPS), which catalyzes an essential step in the aromatic amino acid biosynthetic pathway. We report the genetic engineering of herbicide resistance by stable integration of the petunia EPSPS gene into the tobacco chloroplast genome using the tobacco or universal vector. Southern blot analysis confirms stable integration of the EPSPS gene into all of the chloroplast genomes (5000-10,000 copies per cell) of transgenic plants. Seeds obtained after the first self-cross of transgenic plants germinated and grew normally in the presence of the selectable marker, whereas the control seedlings were bleached. While control plants were extremely sensitive to glyphosate, transgenic plants survived sprays of high concentrations of glyphosate. Chloroplast transformation provides containment of foreign genes because plastid transgenes are not transmitted by pollen. The escape of foreign genes via pollen is a serious environmental concern in nuclear transgenic plants because of the high rates of gene flow from crops to wild weedy relatives.

Darmency, H. (1994). "The Impact of Hybrids between Genetically-Modified Crop Plants and Their Related Species - Introgression and Weediness." Molecular Ecology 3(1): 37-40.

Assessing the impact of hybrids between transgenic plants and nontarget wild species involves answering several questions such as: (i) what are the hybridization and introgression rates; (ii) what is the behaviour of a transgene in a wild population; and (iii) what will be the consequences of the expression of a transgene in a wild population? These issues are discussed using results from experiments on oilseed rape and wild related Brassiceae. Evidence is given of large variations in the estimates of cross-fertilization probabilities. The first stage of introgression into wild populations is demonstrated to occur spontaneously through back-crossing. Population analysis may also be valuable to detect traces of past introgression. Data from the literature on weed biology, and especially herbicide resistance, are used to illustrate the behaviour of a new gene in weed populations. The need for computer models simulating the introgression process is stressed.

Darmency, H. and A. Fleury (2000). "Mating system in Hirschfeldia incana and hybridization to oilseed rape." Weed Research 40(2): 231-238.

Concerns have been raised about the possibility of sexual transfer of herbicide resistance genes from transgenic crops towards weedy relatives. The average rate of spontaneous hybridization between Hirschfeldia incana (L.) Lagreze-Fossat and oilseed rape (Brassica napus L.) was 0.6 hybrids per plant over 3 years of field experiments using herbicide-resistant oilseed rape as a pollen donor. Self-incompatibility was shown to be the mating system of most individuals within a population of H. incana, although some plants had some ability to self- fertilize, which could mitigate gene flow. Back-crossing interspecific hybrids to H. incana over five generations showed that introgression was not successful in our experiment.

Davenport, I. J., M. J. Wilkinson, et al. (2000). "Quantifying gene movement from oilseed rape to its wild relatives using remote sensing." International Journal of Remote Sensing 21(18): 3567-3573.

The potential environmental risks due to gene flow from genetically modified (GM) crops into wild plant populations are currently of great concern. Of particular interest is gene flow from GM oilseed rape (Brassica napus) into its wild parental species B. rapa and B. oleracea, with which it forms spontaneous hybrids. The rate of hybridization is best determined empirically under a wide variety of field conditions. A procedure for quantifying hybrid formation using remote sensing over a large area of southern England is described. Satellite sensor images were used to identify localities where gene flow was most likely by searching for oilseed rape fields adjacent to regions where the parent plants occur, namely rivers and cliff-tops. These sites were visited and screened for hybrids. A single hybrid was observed in an area of over 16 000 km(2). We use these data to suggest a strategy to minimise gene flow following commercial scale release of GM B. napus across Europe and propose a procedure that may allow post-release containment.

De Marchis, F., M. Bellucci, et al. (2003). "Measuring gene flow from two birdsfoot trefoil (Lotus corniculatus) field trials using transgenes as tracer markers." Molecular Ecology 12(6): 1681-1685.

Genetic engineering is becoming a useful tool in the improvement of plants but concern has been expressed about the potential environmental risks of releasing genetically modified (GM) organisms into the environment. Attention has focused on pollen dispersal as a major issue in the risk assessment of transgenic crop plants. In this study, pollen-mediated dispersal of transgenes via cross-fertilization was examined. Plants of Lotus corniculatus L. transformed with either the Escherichia coli asparagine synthetase gene asn A or the beta-glucuronidase gene uid A, were used as the pollen donor. Nontransgenic plants belonging to the species L. corniculatus L., L. tenuis Waldst. and Kit. ex Willd, and L. pedunculatus Cav., were utilized as recipients. Two experimental fields were established in two areas of central Italy. Plants carrying the uid A gene were partially sterile, therefore only the asn A gene was used as a tracer marker. No transgene flow between L. corniculatus transformants and the nontransgenic L. tenuis and L. pedunculatus plants was detected. As regards nontransgenic L. corniculatus plants, in one location flow of asn A transgene was detected up to 18 m from the 1.8 m(2) donor plot. In the other location, pollen dispersal occurred up to 120 m from the 14 m(2) pollinating plot.

Decker-Walters, D. S., J. E. Staub, et al. (2002). "Diversity in free-living Populations of Cucurbita pepo (Cucurbitaceae) as assessed by random amplified polymorphic DNA." Systematic Botany 27(1): 19-28.

One area of risk assessment for transgenic crops concerns cross-compatible wild and weedy relatives, In squash (Cucurbita pepo), free-living populations are diverse in their distributions, ecologies, histories, and genetic and phenotypic compositions. As part of the effort to understand this diversity random amplified polymorphic DNA (RAPD) data were collected from 37 wild or weedy populations and 16 cultivars, which together represented all infraspecific taxa of C. pepo. Twenty-six primers yielded 70 scorable and variable markers. The presence/absence of bands for these markers produced a data matrix which was analyzed using cluster analysis, The analysis confirmed the relationships among infraspecific taxa that had been revealed, in part, in previous genetic analyses (e.g., isozymes, chloroplast DNA restriction-site mutations, inter simple sequence repeats). Also supported were findings of varying degrees of gene flow from cultivars into free-living populations. Some of the RAPID variation in subsp. ovifera var, ozarkana populations was found to be correlated with the distribution of the drainage systems along which these populations are dispersed, Finally, the RAPD results support the idea that transgenic gene flow experiments with free-living populations should consider using representatives from each of the three free-living taxa, as well as from genetically or ecologically distinct populations within these taxa.

Degrassi, G., N. Alexandrova, et al. (2003). "Databases on biotechnology and biosafety of GMOs." Environ Biosafety Res 2(3): 145-160.

Due to the involvement of scientific, industrial, commercial and public sectors of society, the complexity of the issues concerning the safety of genetically modified organisms (GMOs) for the environment, agriculture, and human and animal health calls for a wide coverage of information. Accordingly, development of the field of biotechnology, along with concerns related to the fate of released GMOs, has led to a rapid development of tools for disseminating such information. As a result, there is a growing number of databases aimed at collecting and storing information related to GMOs. Most of the sites deal with information on environmental releases, field trials, transgenes and related sequences, regulations and legislation, risk assessment documents, and literature. Databases are mainly established and managed by scientific, national or international authorities, and are addressed towards scientists, government officials, policy makers, consumers, farmers, environmental groups and civil society representatives. This complexity can lead to an overlapping of information. The purpose of the present review is to analyse the relevant databases currently available on the web, providing comments on their vastly different information and on the structure of the sites pertaining to different users. A preliminary overview on the development of these sites during the last decade, at both the national and international level, is also provided.

Degrieck, I., E. Van Bockstaele, et al. (2001). "Gene flow from a large scale release of genetically modified herbicide tolerant and hybrid winter oilseed rape (Brassica napus L.)." Meded Rijksuniv Gent Fak Landbouwkd Toegep Biol Wet 66(3b): 437-438.

One of the major concerns regarding the cultivation of transgenic crops is the uncontrolled spread of transgenes among fields or to related wild species. To address this concern a long-term study has been set up to assess the amount of gene flow that is occurring from a large scale field trial of genetically modified herbicide tolerant and hybrid (GMHTH) oilseed rape. During the first year of the project, outcrossing of the herbicide tolerance gene from a large scale release of GMHTH winter oilseed rape to a non-transgenic oilseed rape crop in the vicinity and to wild relatives in the environment has been monitored. After harvesting seeds on oilseed rape plants or wild relatives, the seeds are sown in the greenhouse. Seedlings are sprayed with the herbicide on two different occasions. In this way escapes of the first treatment that are not transgenic will be eliminated. To confirm the transgene state of the surviving plants, leaf material is collected from resistant plants. DNA is extracted and the material is examined for the presence of the herbicide tolerance gene by means of a PCR assay. Results on the levels of cross pollination will be discussed.

Desplanque, B., P. Boudry, et al. (1999). "Genetic diversity and gene flow between wild, cultivated and weedy forms of Beta vulgaris L-(Chenopodiaceae), assessed by RFLP and microsatellite markers." Theoretical and Applied Genetics 98(8): 1194-1201.

Beets belonging to the species Beta vulgaris L. can be found in crop, wild and weedy forms, all of which are interfertile. We studied the intra-specific genetic relationships of about 300 individuals from 54 populations of various French geographic origins using nuclear molecular markers (five single-copy RFLP loci and one microsatellite locus). The patterns of diversity were congruent for both types of markers. Genetic diversity in wild beets appeared to be high, both in term of allele number and observed heterozygosity, whereas the narrowness of the cultivated-beet gene pool was confirmed. Genetic distances between all forms showed that weed beets in northern France are intermediates between sugar beet and inland wild beets in south-western France. This analysis allowed us to infer the paternal origin of weed beets and furthermore, is in agreement with a previous study which focused on their maternal origin: weed beet infesting sugar-beet fields originated from accidental and recurrent hybridization between cultivated lines and ruderal inland wild beets during the production of commercial seeds in southwestern France. Inland wild beets are genetically close to Mediterranean coastal wild beets, but differ from other coastal forms (from Biscay, Brittany and northern France). The study of gene flow in the beet complex contributes to the risk assessment of transgenic beets.

Desplanque, B., N. Hautekeete, et al. (2002). "Transgenic weed beets: possible, probable, avoidable?" Journal of Applied Ecology 39(4): 561-571.

1. Weed beets pose a serious problem for sugar beet Beta vulgaris crops. Traditionally, the only efficient method of weed control has been manual removal, but the introduction of transgenic herbicide-tolerant sugar beets may provide an alternative solution because non-tolerant weed beets can be destroyed by herbicide. We evaluated the possibility that new, transgenic, weed beets may arise by gene flow between wild and crop plants. 2. In a study area in northern France, weed beets were present in variable densities in sugar beet fields of up to 80 weed beet plants m(-2) . Weed beets arise from a long- lived seed bank, with seeds germinating from depths of 5 cm or less. In addition, diploid F-1 crop-wild hybrids and triploid variety bolters (individuals with a low vernalization requirement) were present in low densities in virtually all sugar beet fields. We found gene flow to be possible between all forms, illustrated by both overlapping flowering periods in the field and successful controlled cross-pollinations. 3. The F-1 crop-wild hybrids result from pollination in the seed- production region by wild plants possessing the dominant bolting allele B for flowering without experiencing a period of cold. In the case of a transgene for herbicide tolerance incorporated into male-sterile seed-bearer plants, such hybrids will contain both the herbicide-tolerance and the bolting allele. Contamination of the fields by transgenic weed beets will be the result unless bolters are removed manually. The same will apply in the case of a cytoplasmically inherited transgene. 4. Incorporation of the transgene into the pollinator plants will prevent the immediate formation of transgenic weed beets. However, in sugar beet fields, variety bolters may successfully cross-pollinate with weed beets in neighbouring fields. The use of diploid pollinator plants instead of tetraploids will considerably enhance gene flow towards wild beets, and is not, therefore, an attractive option. 5. In conclusion, the appearance of transgenic weed beets is possible but can best be retarded if the transgene for herbicide tolerance is incorporated into the tetraploid pollinator breeding line.

Devlin, R. H., L. F. Sundstrom, et al. (2006). "Interface of biotechnology and ecology for environmental risk assessments of transgenic fish." Trends Biotechnol 24(2): 89-97.

Genetically engineered fish with enhanced phenotypic traits have yet to be implemented into commercial applications. This is partly because of the difficulties in reliably predicting the ecological risk of transgenic fish should they escape into the wild. The ecological consequences of the phenotypic differences between transgenic and wild-type fish, as determined in the laboratory, can be uncertain because of genotype-by-environment effects (GXE). Additionally, we are limited in our ability to extrapolate simple phenotypes to the complex ecological interactions that occur in nature. Genetic background can also shape the phenotypic effects of transgenes, which, over time and among different wild populations, can make risk assessments a continuously evolving target. These uncertainties suggest that assessments of transgenic fish in contained facilities need to be conducted under as wide a range of conditions as possible, and that efficacious physical and biological containment strategies remain as crucial approaches to ensure the safe application of transgenic fish technology.

DiFazio, S. P., S. Leonardi, et al. (1999). Assessing potential risks of transgene escape from fiber plantations. Gene flow and agriculture: relevance for transgenic crops. Proceedings of a symposium held at Keele, UK on 12-14 April 1999. %M 19991606421, Keele, UK, 12-14 April 1999.

Woody crops such as trees pose difficult obstacles for genetic risk analysis because of their long generation times, large size, and potential for long distance dispersal of pollen and seed. This necessitates reliance on established stands for retrospective studies of gene flow, and simulation models to assess the consequences of introducing new genes into the environment. These approaches are being used to assess potential risks of large-scale cultivation of transgenic hybrid poplar (<i>Populus</i> spp.). To predict gene flow from hybrid plantations, it is necessary to understand both the dynamics of gene movement within and between populations, and the ability of hybrid trees to produce fit progeny. In a study of gene flow in the vicinity of 2 industrial plantations of hybrid poplar (<i>P. trichocarpa</i> x <i>P. deltoides</i>) in western Oregon (River Ranch and Clatskanie), up to 3.8% of progeny of wild females growing near the plantations were fathered by hybrid males. Also, hybrid seedlings established and grew at about the same rate as wild seedlings. Data from these field studies will be integrated in a spatial simulation model which is currently under development. The model will be used to identify the genetic and ecological parameters most important for predicting the spread of herbicide- and insect-resistance transgenes over space and time. Potential economic and agronomic significance of transgene spread will also be assessed.

DiFazio, S. P., G. T. Slavov, et al. (2004). Gene flow from tree plantations and implications for transgenic risk assessment. Plantation Forest Biotechnology for the 21st Century. C. Walter and M. Carson, Research Signpost: 405-422.

Gene flow is a major determinant of impacts of forest tree plantations on surrounding populations and ecosystems. Realistic predictions of gene flow are therefore essential for scientifically credible assessments of the impacts of transgenic plantations. The choice of methods for measuring gene flow will be dictated by the organism and environment under study, the availability of tools and resources, and the desired scope of inference. Methods include direct tracking of propagule movement, parentage analysis, and analysis of genetic diversity in seeds, seedlings, and pollen. Gene flow estimates can be integrated with ecological and demographic data in spatially-explicit simulation models to allow projections of transgene dispersal over large areas and long time frames. Such models allow exploration of a large number of scenarios of plantation cultivation, and help to identify the key parameters controlling gene flow. We describe a simulation study of gene flow from hybrid poplar plantations that illustrates some of the key issues in estimating and modelling transgene flow from plantations. For example, the results suggested that accurate estimates of long-distance gene flow are considerably more important to prediction of transgene dispersal than are estimates of local (<1 km) dispersal patterns.

DiFazio, S. P., G. T. Slavov, et al. (2006). "Introgression of transgenes into perennial plant populations." Submitted.

Dill, G. M. (2005). "Glyphosate-resistant crops: history, status and future." Pest Manag Sci JT - Pest management science. 61(3): 219-224.

The commercial launch of glyphosate-resistant soybeans in 1996 signaled the beginning of a new era in weed management in row crops. Today, over 80% of the soybeans grown in the USA are glyphosate resistant. Since that time, many crops have been transformed that have allowed crop applications of many classes of herbicide chemistries. Crops currently under production include maize, soybean, cotton and canola. Transformation technology and selection methods have improved and the rate of development as well as the breadth of crops being considered as commercial targets has increased. On the basis of recent adoption rates by growers around the world, it appears that glyphosate-resistant crops will continue to grow in number and in hectares planted. However, global public acceptance of biotechnology-derived products will continue to impact the rate of adoption of this and other new innovations derived from transformation technology.

Doebley, J. (1990). "Molecular Evidence for Gene Flow among Zea Species - Genes Transformed into Maize through Genetic-Engineering Could Be Transferred to Its Wild Relatives, the Teosintes." Bioscience 40(6): 443-448.

Doty, S. L., C. A. James, et al. (2007). "Enhanced phytoremediation of volatile environmental pollutants with transgenic trees." Proc Natl Acad Sci U S A 104(43): 16816-16821.

Small, volatile hydrocarbons, including trichloroethylene, vinyl chloride, carbon tetrachloride, benzene, and chloroform, are common environmental pollutants that pose serious health effects. We have developed transgenic poplar (Populus tremula x Populus alba) plants with greatly increased rates of metabolism and removal of these pollutants through the overexpression of cytochrome P450 2E1, a key enzyme in the metabolism of a variety of halogenated compounds. The transgenic poplar plants exhibited increased removal rates of these pollutants from hydroponic solution. When the plants were exposed to gaseous trichloroethylene, chloroform, and benzene, they also demonstrated superior removal of the pollutants from the air. In view of their large size and extensive root systems, these transgenic poplars may provide the means to effectively remediate sites contaminated with a variety of pollutants at much faster rates and at lower costs than can be achieved with current conventional techniques.

Douville, M., F. Gagne, et al. (2007). "Occurrence and persistence of Bacillus thuringiensis (Bt) and transgenic Bt corn cry1Ab gene from an aquatic environment." Ecotoxicol Environ Saf 66(2): 195-203.

Genetically modified corn crops and suspensions of Bacillus thuringiensis (Bt) are currently used to control pest infestations of insects of the Lepidoptera family. For this purpose, the cry1Ab gene coding for protein delta-endotoxin derived from B. thuringiensis kurstaki (Btk), which is highly toxic to these insects, was inserted and expressed in corn. The aims of this study were to examine the occurrence and persistence of the cry1Ab gene from Btk and Bt corn in aquatic environments near fields where Bt corn was cultivated. First, an optimal DNA preparation and extraction methodology was developed to allow for quantitative gene analysis by real-time polymerase chain reaction (qPCR) in various environmental matrices. Second, surface water and sediment were spiked in vitro with genomic DNA from Bt or Bt corn to evaluate the persistence of cry1Ab genes. Third, soil, sediment, and water samples were collected before seeding, 2 weeks after pollen release, and after corn harvesting and mechanical root remixing in soils to assess cry1Ab gene content. DNA was extracted with sufficient purity (i.e., low absorbance at 230 nm and absence of PCR-inhibiting substances) from soil, sediment, and surface water. The cry1Ab gene persisted for more than 21 and 40 days in surface water and sediment, respectively. The removal of bacteria by filtration of surface water samples did not significantly increase the half-life of the transgene, but the levels were fivefold more abundant than those in unfiltered water at the end of the exposure period. In sediments, the cry1Ab gene from Bt corn was still detected after 40 days in clay- and sand-rich sediments. Field surveys revealed that the cry1Ab gene from transgenic corn and from naturally occurring Bt was more abundant in the sediment than in the surface water. The cry1Ab transgene was detected as far away as the Richelieu and St. Lawrence rivers (82 km downstream from the corn cultivation plot), suggesting that there were multiple sources of this gene and/or that it undergoes transport by the water column. Sediment-associated cry1Ab gene from Bt corn tended to decrease with distance from the Bt cornfield. Sediment concentrations of the cry1Ab gene were significantly correlated with those of the cry1Ab gene in surface water (R=0.83;P=0.04). The data indicate that DNA from Bt corn and Bt were persistent in aquatic environments and were detected in rivers draining farming areas.

Driessen, S., M. Pohl, et al. (2001). "RAPD-PCR analysis of the genetic origin of sea beet (Beta vulgaris ssp maritima) at Germany's Baltic Sea coast." Basic and Applied Ecology 2(4): 341-349.

The spread of plant populations into new habitats and their establishment there is an important object of ecological research, particularly for those plant species consisting of cultivated, weedy and wild forms. One of these species is Beta vulgaris L., which is taxonomically divided into the subspecies vulgaris (sugar beet, Swiss chard, red beet, some weedy beet forms) and maritima (sea beet). In northeastern Europe, the distribution range of the different Beta subspecies is not well known. The aim of this study was to investigate the origin of sea beet populations at the Baltic Sea coast of Germany by collecting seed samples and performing RAPD-PCR analysis. Theoretically, the spread and the establishment of beet populations in the wild could be the result of various different processes: (1) introduction of seeds from wild populations, (2) naturalization of cultivated or weedy types after introduction into wild habitats, and (3) a combination of (1) and (2) with subsequent hybridisation and evolution into an intermediate genotype. Genetic analysis suggests that the Baltic Sea coast populations are pure wild beets (1) and not weedy or escaped sugar beets (2 or 3). In a UPGMA phenogram, the wild and the cultivated beets could be clearly distinguished from one another. In addition to the strong evidence that German sea beet originated from Danish sea beet, the possibility of seed disperal between these groups via seawater was demonstrated. Beta vulgaris seeds survived a long period in seawater and up to 2% of the seeds still germinated after 28 weeks. The fact that sea beet populations can now be found sympatrically to flowering sugar beets and weed beets in coastal agricultural areas offers new possibilities of gene flow. This is important fundamental knowledge for the risk assessment of gene flow from transgenic sugar beet.

Duan, J. J., M. Marvier, et al. (2008). "A Meta-Analysis of Effects of Bt Crops on Honey Bees (Hymenoptera: Apidae)." PLoS ONE 3(1): e1415.

Background: Honey bees (Apis mellifera L.) are the most important pollinators of many agricultural crops worldwide and are a key test species used in the tiered safety assessment of genetically engineered insect-resistant crops. There is concern that widespread planting of these transgenic crops could harm honey bee populations. Methodology/Principal Findings: We conducted a meta-analysis of 25 studies that independently assessed potential effects of Bt Cry proteins on honey bee survival (or mortality). Our results show that Bt Cry proteins used in genetically modified crops commercialized for control of lepidopteran and coleopteran pests do not negatively affect the survival of either honey bee larvae or adults in laboratory settings. Conclusions/Significance: Although the additional stresses that honey bees face in the field could, in principle, modify their susceptibility to Cry proteins or lead to indirect effects, our findings support safety assessments that have not detected any direct negative effects of Bt crops for this vital insect pollinator.

Duke, S. O. (2003). "Weeding with transgenes." Trends Biotechnol 21(5): 192-195.

Transgenes promise to reduce insecticide and fungicide use but relatively little has been done to significantly reduce herbicide use through genetic engineering. Recently, three strategies for transgene utilization have been developed that have the potential to change this. These are the improvement of weed-specific biocontrol agents, enhancement of crop competition or allelopathic traits, and production of cover crops that will self-destruct near the time of planting. Failsafe risk mitigation technologies are needed for most of these strategies.

Duke, S. O. (2005). "Taking stock of herbicide-resistant crops ten years after introduction." Pest Manag Sci JT - Pest management science. 61(3): 211-218.

Since transgenic, bromoxynil-resistant cotton and glufosinate-resistant canola were introduced in 1995, planting of transgenic herbicide-resistant crops has grown substantially, revolutionizing weed management where they have been available. Before 1995, several commercial herbicide-resistant crops were produced by biotechnology through selection for resistance in tissue culture. However, non-transgenic herbicide-resistant crops have had less commercial impact. Since the introduction of glyphosate-resistant soybean in 1996, and the subsequent introduction of other glyphosate-resistant crops, where available, they have taken a commanding share of the herbicide-resistant crop market, especially in soybean, cotton and canola. The high level of adoption of glyphosate-resistant crops by North American farmers has helped to significantly reduce the value of the remaining herbicide market. This has resulted in reduced investment in herbicide discovery, which may be problematic for addressing future weed-management problems. Introduction of herbicide-resistant crops that can be used with selective herbicides has apparently been hindered by the great success of glyphosate-resistant crops. Evolution of glyphosate-resistant weeds and movement of naturally resistant weed species into glyphosate-resistant crop fields will require increases in the use of other herbicides, but the speed with which these processes compromise the use of glyphosate alone is uncertain. The future of herbicide-resistant crops will be influenced by many factors, including alternative technologies, public opinion and weed resistance. Considering the relatively few recent approvals for field testing new herbicide-resistant crops and recent decisions not to grow glyphosate-resistant sugarbeet and wheat, the introduction and adoption of herbicide-resistant crops during the next 10 years is not likely to be as dramatic as in the past 10 years.

Dunfield, K. E. and J. J. Germida (2004). "Impact of genetically modified crops on soil- and plant-associated microbial communities." J Environ Qual 33(3): 806-815.

Transgenic or genetically modified plants possess novel genes that impart beneficial characteristics such as herbicide resistance. One of the least understood areas in the environmental risk assessment of genetically modified crops is their impact on soil- and plant-associated microbial communities. The potential for interaction between transgenic plants and plant residues and the soil microbial community is not well understood. The recognition that these interactions could change microbial biodiversity and affect ecosystem functioning has initiated a limited number of studies in the area. At this time, studies have shown the possibility that transgenes can be transferred to native soil microorganisms through horizontal gene transfer, although there is not evidence of this occurring in the soil. Furthermore, novel proteins have been shown to be released from transgenic plants into the soil ecosystem, and their presence can influence the biodiversity of the microbial community by selectively stimulating the growth of organisms that can use them. Microbial diversity can be altered when associated with transgenic plants; however, these effects are both variable and transient. Soil- and plant-associated microbial communities are influenced not only by plant species and transgene insertion but also by environmental factors such as field site and sampling date. Minor alterations in the diversity of the microbial community could affect soil health and ecosystem functioning, and therefore, the impact that plant variety may have on the dynamics of the rhizosphere microbial populations and in turn plant growth and health and ecosystem sustainability, requires further study.

Eaglesham, A., r. Bessin, et al. (2005). Agricultural Biotechnology: Beyond food and Energy to Health and the Environments. Ithaca, NY, National Agricultural Biotechnology Council.

Eijlander, R. and W. J. Stiekema (1994). "Biological Containment of Potato (Solanum-Tuberosum) - Outcrossing to the Related Wild-Species Black Nightshade (Solanum-Nigrum) and Bittersweet (Solanum-Dulcamara)." Sexual Plant Reproduction 7(1): 29-40.

The biological containment of the potato (Solanum tuberosum) was assessed by establishing the crossability of this tuberous crop with the related wild non-tuberous species in The Netherlands, black nightshade (S. nigrum) and bittersweet (S. dulcamara). To circumvent crossability barriers, genotypes with different ploidy number were employed and crosses were performed under different environmental conditions. S. dulcamara was shown to be incongruent with potato at all ploidy levels, while S. nigrum displayed unilateral incompatibility. If S. nigrum was emasculated and used as female, fertilization by potato pollen resulted in berry set and seed development. Emasculation of S. nigrum was essential in this cross, because analysis of the fertilization process demonstrated that this species is highly self-compatible and potato pollen was outcompeted by pollen of S. nigrum. The hybrid seeds derived from this cross did not mature and appeared not to be viable. By application of the technique of embryo rescue of immature embryos, hybrid plants could be obtained. However, these hybrid plants proved to be sterile. These data demonstrate that gene flow by pollen dispersal from potato to its most common wild relatives in Western Europe is highly unlikely. The potato is thus a naturally contained species in this part of the world.

Ellstrand, N. C. (2002). Gene flow from transgenic crops to wild relatives: What have we learned, what do we know, and what do we need to know? Ecological and Agronomic Consequences of Gene Flow from Transgenic Crops to Wild Relatives, The Ohio State University, Columbus, Ohio.

Ellstrand, N. C. (2003). "Current knowledge of gene flow in plants: implications for transgene flow." Philos Trans R Soc Lond B Biol Sci 358(1434): 1163-1170.

Plant evolutionary biologists' view of gene flow and hybridization has undergone a revolution. Twenty-five years ago, both were considered rare and largely inconsequential. Now gene flow and hybridization are known to be idiosyncratic, varying with the specific populations involved. Gene flow typically occurs at evolutionarily significant rates and at significant distances. Spontaneous hybridization occasionally has important applied consequences, such as stimulating the evolution of more aggressive invasives and increasing the extinction risk for rare species. The same problems have occurred for spontaneous hybridization between crops and their wild relatives. These new data have implications for transgenic crops: (i) for most crops, gene flow can act to introduce engineered genes into wild populations; (ii) depending on the specific engineered gene(s) and populations involved, gene flow may have the same negative impacts as those observed for traditionally improved crops; (iii) gene flow's idiosyncratic nature may frustrate management and monitoring attempts; and (iv) intercrop transgene flow, although rarely discussed, is equally worthy of study.

Engels, J. M. M., M. C. d. Vicente, et al. (2006). "Centres of Crop Diversity and/or Origin, Genetically Modified Crops and Implications for Plant Genetic Resources Conservation [electronic resource]." Genetic Resources and Crop Evolution 53(8): 1675-1688.

The concept of centres of crop diversity and/or origin of agriculture is briefly reviewed. The conservation status of crop genetic resources, either ex situ or in situ, cultivated or wild, has been assessed for species of the Central American and Mexican centre, demonstrating that that region is indeed one of the important centres of crop diversity for human kind. Furthermore, biotechnological developments with regard to the creation and spread of genetically modified crops have been analyzed. The likelihood of unintentional introgression of genetically modified traits into conventional seed lots, crops as well as into germplasm collections have been assessed. Related biosafety measures as well as the possible implications of intellectual property rights on transgenic crops and/or genes are being discussed vis-a-vis the possible implications they might have for germplasm management. The Central American crop genetic resources situation has been used as a (3z(Bcase study(3y(B to illustrate the potential impact of the spreading of GM varieties on the genetic diversity in genebanks and farmers' fields and the need for effective and efficient conservation efforts. Conservation management strategies and practices are being proposed of mitigate the potential negative impact of GM crops on the conservation efforts.

EPA (1992). Framework for ecological risk assessment: 1-41.

Publication of this report, “Framework for Ecological Risk Assessment” (Framework Report), is a first step in a long-term program to develop risk assessment guidelines for ecological effects. EPA has been developing risk assessment guidelines primarily for human health effects for several years. In 1986, EPA issued five such guidelines, Including cancer, developmental toxicity, and exposure assessment (51 Federal Register 33992-34054, 24 September 1986). Although EPA had issued guidance for cancer risk assessment 10 years earlier (41 Federal Register 21402, 1976), the 1986 guidelines substantially enlarged the scope of EPA's formal guidance by covering additional health topics and by covering all areas in much greater depth. Each of the guidelines was a product of several years of discussion and review involving scientists and policymakers from EPA, other Federal agencies, universities, industry, public interest groups, and the general public.

EPA (2000). FIFRA Scientific Advisory Panel Meeting Report.

Facon, B., B. J. Genton, et al. (2006). "A general eco-evolutionary framework for understanding bioinvasions." Trends in Ecology & Evolution 21(3): 130-135.

Studies of bioinvasions have revealed various strategies of invasion, depending on the ecosystem invaded and the alien species concerned. Here, we consider how migration (as a demographic factor), as well as ecological and evolutionary changes, affect invasion success. We propose three main theoretical scenarios that depend on how these factors generate the match between an invader and its new environment. Our framework highlights the features that are common to, or differ among, observed invasion cases, and clarifies some general trends that have been previously highlighted in bioinvasions. We also suggest some new directions of research, such as the assessment of the time sequence of demographic, genetic and environmental changes, using detailed temporal surveys.

FAO (2004). Preliminary review of biotechnology in forestry, including genetic modification. Forest Genetic Resources Working Paper FGR/59E, Forest Resources Development Service, Forest Resources Division. Rome, Italy.

Farnum, P., A. l. Lucier, et al. (2007). "Ecological and population genetics research imperatives for transgenic trees." Tree Genetics & Genomes.

Felber, F., G. Kozlowski, et al. (2007). Genetic and ecological consequences of transgene flow to the wild flora. Green Gene Technology: Research in an Area of Social Conflict. 107: 173-205.

Gene flow from crops to wild relatives by sexual reproduction is one of the major issues in risk assessment for the cultivation of genetically engineered (GE) plants. The main factors which influence hybridization and introgression, the two processes of gene flow, as well as the accompanying containment measures of the transgene, are reviewed. The comparison of risks between Switzerland and Europe highlights the importance of regional studies. Differences were assessed for barley, beet and wheat. Moreover, transgene flow through several wild species acting as bridge (bridge species) has been up to now poorly investigated. indeed, transgene flow may go beyond the closest wild relative, as in nature several wild species complexes hybridize. Its importance is assessed by several examples in Poaceae. Finally, the transgene itself has genetic and ecological consequences that are reviewed. Transgenic hybrids between crops and wild relatives may have lower fitness than the wild relatives, but in several cases, no cost was detected. On the other hand, the transgene provides advantages to the hybrids, in the case of selective value as a Bt transgene in the presence of herbivores. Genetic and ecological consequences of a transgene in a wild species are complex and depend on the type of transgene, its insertion site, the density of plants and ecological factors. More studies are needed for understanding the short and long term consequences of escape of a transgene in the wild.

Ferry, N., E. A. Mulligan, et al. (2006). "Prey-mediated effects of transgenic canola on a beneficial, non-target, carabid beetle." Transgenic Res 15(4): 501-514.

Transgenic plants producing insecticidal proteins from Bacillus thuringiensis (Bt) can control some major insect pests and reduce reliance on sprayed insecticides. However, large scale adoption of this technology has raised concerns about potential negative effects, including evolution of pest resistance to Bt toxins, transgene flow from Bt crops to other plants, and harm to non-target beneficial organisms. Furthermore, concern has also been expressed over the effects this technology may have on biodiversity in general. Ecologically relevant risk assessment is therefore required (Risk = Hazard x Exposure). Transgenic plants that produce Bt toxins to kill insect pests could harm beneficial predators. This might occur directly by transmission of toxin via prey, or indirectly by toxin-induced reduction in prey quality (Hazard). To test these hypotheses, we determined the effects of Bt-producing canola on a predatory ground beetle (Pterostichus madidus) fed larvae of diamondback moth (Plutella xylostella) that were either susceptible or resistant to the Bt toxin. Survival, weight gain, and adult reproductive fitness did not differ between beetles fed prey reared on Bt-producing plants and those fed prey from control plants. Furthermore, while Bt-resistant prey was shown to deliver high levels of toxin to the beetle when they were consumed, no significant impact upon the beetle was observed. Subsequent investigation showed that in choice tests (Exposure), starved and partially satiated female beetles avoided Bt-fed susceptible prey, but not Bt-fed resistant prey. However, in the rare cases when starved females initially selected Bt-fed susceptible prey, they rapidly rejected them after beginning to feed. This prey type was shown to provide sufficient nutrition to support reproduction in the bioassay suggesting that Bt-fed susceptible prey is acceptable in the absence of alternative prey, however adults possess a discrimination ability based on prey quality. These results suggest that the direct effects of Bt-producing canola on predator life history was minimal, and that predators' behavioural preferences may mitigate negative indirect effects of reduced quality of prey caused by consumption of Bt-producing plants. The results presented here therefore suggest that cultivation of Bt canola may lead to conservation of non-target predatory and scavenging organisms beneficial in pest control, such as carabids, and may therefore provide more sustainable agricultural systems than current practices. In addition, minimal impacts on beneficial carabids in agro-ecosystems suggest that Bt canola crops are likely to be compatible with integrated pest management (IPM) systems.

Finucane, M. L. and J. L. Holup (2005). "Psychosocial and cultural factors affecting the perceived risk of genetically modified food: an overview of the literature." Soc Sci & Med 60: 1603-1612.

Firbank, L., M. Lonsdale, et al. (2005). "Reassessing the environmental risks of GM crops." Nature Biotechnology 23(12): 1475-1476.

A decade has now passed since the first commercial releases of genetically modified (GM) crops, a period marked by great controversy over the potential ecological effects of this technology. As a result, the procedures for environmental risk assessment and monitoring have developed rapidly to become formalized within scientific1, 2, 3 and regulatory frameworks, such as the Cartagena Protocol and the European Commission's (EC's) Directive 2001/18. In practice, these have tended to focus upon risks that can be researched at the small scale, at the expense of assessing the much larger scale risks and benefits of changes to the farming system.

Flach, B. (2006). Netherlands, Biotechnology, Dutch government supports GM crop research. USDA Foreign Agricultural Service, Global Agriculture Information Network.

The Dutch Ministry of Agriculture, Nature and Food Quality tasked the Wageningen University to develop a genetically modified (GM) potato with resistance to late blight (Phytophthora infestans). Six field trials with the GM maize hybrid Mon810 will be conducted this year to establish the size of buffer zones for coexistence purposes.

Flannery, M.-L., C. Meade, et al. (2005). "Employing a composite gene-flow index to numerically quantify a crop's potential for gene flow: an Irish perspective." Environ Biosafety Res 4(1): 29-43.

Guidelines to ensure the efficient coexistence of genetically modified (GM) and conventional crops are currently being considered across the European Union. The purpose of this strategy is to describe the measures a farmer must adopt to minimize the admixture of GM and non-GM crops. Minimizing pollen/seed-mediated gene flow between GM and non-GM crops is central to successful coexistence. However no system is currently available to permit the numeric quantification of a crop's propensity for pollen/seed-mediated gene flow. The provision of such a system could permit a background level of gene flow, specific for a particular conventional crop, to be calculated. Here we present a gene flow index model implemented using the principal arable crops in Ireland as a model dataset. The objective of this research was to establish a baseline gene flow data set for Ireland's primary conventional crops through the provision of a simple numerical index. This Gene Flow Index (GFI) incorporates four strands of crop-mediated gene flow (crop pollen-to-crop, crop pollen-to-wild, crop seed-to-volunteer and crop seed-to-feral) into a format that permits the calculation of a crop's gene flow potential. Responsive to regional parameters, we have applied the model to sugar beet, oilseed rape, potato, ryegrass, maize, wheat and barley. We propose that the attained indices will highlight those crops that require additional measures in order to minimize gene flow in accordance with anticipated coexistence guidelines.

Flores, S., D. Saxena, et al. (2005). "Transgenic Bt plants decompose less in soil than non-Bt plants." Soil Biology & Biochemistry 37(6): 1073-1082.

Bt plants are plants that have been genetically modified to express the insecticidal proteins (e.g. Cry1Ab, Cry1Ac, Cry3A) from subspecies of the bacterium, Bacillus thuringiensis (Bt), to kill lepidopteran pests that feed on corn, rice, tobacco, canola, and cotton and coleopteran pests that feed on potato. The biomass of these transgenic Bt plants (Bt+) was decomposed less in soil than the biomass of their near-isogenic non-Bt plant counterparts (Bt-). Soil was amended with 0.5, 1, or 2% (wt wt(-1)) ground, dried (50 degrees C) leaves or stems of Bt corn plants; with 0.5% (wt wt(-1)) ground, dried biomass of Bt rice, tobacco, canola, cotton, and potato plants; with biomass of the near-isogenic plants without the respective cry genes; or not amended. The gross metabolic activity of the soil was determined by CO2 evolution. The amounts of C evolved as CO2 were significantly lower from soil microcosms amended with biomass of Bt plants than of non-Bt plants. This difference occurred with stems and leaves from two hybrids of Bt corn, one of which had a higher C:N ratio than its near-isogenic non-Bt counterpart and the other which had essentially the same C:N ratio, even when glucose, nitrogen (NH4NO3), or glucose plus nitrogen were added with the biomass. The C:N ratios of the other Bt plants (including two other hybrids of Bt corn) and their near-isogenic non-Bt counterparts were also not related to their relative biodegradation. Bt corn had a significantly higher lignin content than near-isogenic non-Bt corn. However, the lignin content of the other Bt plants, which was significantly lower than that of both Bt and non-Bt corn, was generally not statistically significantly different, although 10-66% higher, from that of their respective non-Bt near-isolines. The numbers of culturable bacteria and fungi and the activity of representative enzymes involved in the degradation of plant biomass were not significantly different between soil amended with biomass of Bt or non-Bt corn. The degradation of the biomass of all Bt plants in the absence of soil but inoculated with a microbial suspension from the same soil was also significantly less than that of their respective inoculated non-Bt plants. The addition of streptomycin, cycloheximide, or both to the soil suspension did not alter the relative degradation of Bt+ and Bt - biomass, suggesting that differences in the soil microbiota were not responsible for the differential decomposition of Bt+ and Bt- biomass. All samples of soil amended with biomass of Bt plants were immunologically positive for the respective Cry proteins and toxic to the larvae of the tobacco hornworm (Manduca sexta), which was used as a representative lepidopteran in insect bioassays (no insecticidal assay was done for the Cry3A protein from potato). The ecological and environmental relevance of these findings is not clear. (c) 2004 Elsevier Ltd. All rights reserved.

Fuchs, M. and D. Gonsalves (2007). "Safety of virus-resistant transgenic plants two decades after their introduction: lessons from realistic field risk assessment studies." Annu Rev Phytopathol 45: 173-202.

Potential safety issues have been raised with the development and release of virus-resistant transgenic plants. This review focuses on safety assessment with a special emphasis on crops that have been commercialized or extensively tested in the field such as squash, papaya, plum, grape, and sugar beet. We discuss topics commonly perceived to be of concern to the environment and to human health--heteroencapsidation, recombination, synergism, gene flow, impact on nontarget organisms, and food safety in terms of allergenicity. The wealth of field observations and experimental data is critically evaluated to draw inferences on the most relevant issues. We also express inside views on the safety and benefits of virus-resistant transgenic plants, and recommend realistic risk assessment approaches to assist their timely deregulation and release.

Funk, C. R. and W. A. Meyer (2001). "70 years of turfgrass improvement at the New Jersey Agricultural Experiment Station." USGA Green Section Record: 19-23.

The genetic improvement of turfgrass was initiated at Rutgers University by H. B. Sprague prior to the Second World War. Dr. Howard B. Sprague, the world-renowned agronomist at Rutgers, included turfgrass science as one of many areas of accomplishment and activity. He recruited Glenn Burton as a Ph.D. student to assist during the mid-1930s. Dr. Sprague believed that velvet bentgrass offered great potential for turfgrass improvement. It required little or no added fertilizer to produce a fine, dense, very attractive turf in shade or full sun, and at high or low mowing. He developed 'Raritan' velvet bentgrass, released in 1940. Turfgrass enthusiasts, including leading golf course superintendents, also cooperated with research personnel of the United States Golf Association and the United States Department of Agriculture at the Arlington Turf Gardens in northern ...

Gaines, T., C. Preston, et al. (2007). "Adventitious presence of herbicide resistant wheat in certified and farm-saved seed lots." Crop Science 47(2): 751-756.

Varietal purity in wheat (Triticum aestivum L.) seed production is necessary for agronomic uniformity and to enable potential market segregation. We conducted a survey of certified and farm-saved seed samples using a nontransgenic imidazolinone-resistant (IR) wheat cultivar in 2004 and 2005 in eastern Colorado. The objective was to compare varietal purity based on type of seed producer and IR wheat history. Ninety-two samples of non-IR varieties were taken from certified and farm-saved seed growers, who either produced or had never produced IR wheat. Adventitious IR seeds were detected using a seed-soaking technique in samples from each producer type and each IR production history. Levels of IR seed ranged from 0 to 11.28%. One certified sample and three farm-saved samples exceeded the 0.1% threshold for off-types in certified wheat seed. Using a two-factor analysis, farm-saved production class and positive IR history increased the estimated proportion of adventitious seed. Based on grower interviews, higher levels of adventitious seed presence were associated with volunteer plants from previous crops of the resistant cultivar and mechanical mixture during harvesting. Production practices for certified seed address these factors and may need to be strengthened if more stringent purity criteria are adopted. This information is important for risk assessment and policy development for potential commercial release of transgenic wheat varieties.

Garcia, M., J. Figueroa, et al. (1998). "Pollen control during transgenic hybrid maize development in Mexico." Crop Science 38(6): 1597-1602.

Pollen containment may be necessary to prevent the dissemination of novel genes from transgenic crops into sexually compatible land races or wild relatives in locations where these are grown or occur naturally in the same vicinity. Routine maize (Zea mays L.) breeding activities employ controlled pollinations and are sometimes done in areas where land races or wild relatives are known to occur. The ability of researchers to control pollen movement and to thereby control the potential pow of novel genes from transgenic maize to land races or wild relatives was investigated. Using white- and yellow-seeded inbreds, pollen control was measured in two mating designs. The ability to control pollen was assessed by observing seed color in pollinations on adjacent plantings intended to trap uncontrolled pollen. In one experiment, the yellow-seeded maize contained a transgene. In this experiment contaminant seeds observed in the white maize were analyzed for the presence of recombinant DNA and the gene expression product. The results from these experiments indicated that routine plant breeding activities can be conducted with completely effective pollen containment if the transgenic line is detasseled and serves as the female for pollination with a nontransgenic male inbred. However, precautions in addition to those used in these experiments are necessary to provide complete control of pollen dissemination if a transgenic male is used to make crosses and approximate to 0.1% outcrossing to adjacent rows is deemed unacceptable.

Garcia-Alonso, M., E. Jacobs, et al. (2006). "A tiered system for assessing the risk of genetically modified plants to non-target organisms." Environ Biosafety Res 5(2): 57-65.

Representatives of the developers of modern agricultural biotechnology are proposing a tiered approach for conducting non-target organism risk assessment for genetically modified (GM) plants in Europe. The approach was developed by the Technical Advisory Group of the EuropaBio Plant Biotechnology Unit (http://www.europabio.org/TAG.htm) and complements other international activities to harmonize risk assessment. In the European Union (EU), the principles and methods to be followed in an environmental risk assessment for the placing on the market of GM plants are laid out in Annex II of Directive 2001/18/EC on the deliberate release into the environment of GMOs, Commission Decision 2002/623/EC and Regulation (EC) No. 1829/2003. Additional information is provided in the European Food Safety Authority guidance document of 2004. However, risk assessment for effects to non-target organisms could benefit from further clarification and remains the subject of much discussion in Europe. The industry-wide approach developed by EuropaBio is based on the fundamental steps of risk evaluation, namely hazard and exposure assessment. It follows a structured scheme including assessment planning, product characterization and assessment of hazard/exposure (Tier 0), single high dose and dose response testing (Tier 1), refined hazard characterization and exposure assessment (Tier 2) and further refined risk assessment experiments (Tier 3). An additional tier (Tier 4) was included to reflect the fact that post-market activities such as monitoring are required under Directive 2001/18/EC. The approach is compatible with conditions of commercial release in the EU and around the world.

Garnier, A. and J. Lecomte (2006). "Using a spatial and stage-structured invasion model to assess the spread of feral populations of transgenic oilseed rape." Ecological Modelling 194(1-3): 141-149.

The risk of roadside verge invasion by transgenic plants is favoured when a cultivated species can persist outside fields as feral populations. we chose oilseed rape as a model species to evaluate the spread of genetically modified herbicide tolerant (GMHT) feral populations under selection pressure (herbicide spraying) in the medium term. We developed a stepwise invasion model that combines stage-structured dynamics (via a leslie matrix) and seed dispersal (via a mixture of two kernels) within an integro-differential equation. Modelling choices were made to conform to our intention to obtain methodological insight about the necessity to integrate long-distance seed dispersal in models of gene flow among oilseed rape. We thus assumed that roadside verges are a one-dimensional and uniformly suitable habitat and that events of dispersal and demography are deterministic. We performed elasticity analyses of population growth rate and invasion speed to highlight the determinants of population demography and spread. Rare events of long-distance dispersal controlled population spread. The risk of road verge invasion by feral populations of GMHT oilseed rape under selection pressure is thus real and does exist, since it was proved experimentally that oilseed rape can be dispersed by vehicles. Models of oilseed rape should then include long-distance seed dispersal otherwise they would underestimate feral population spread. Population growth rate and invasion speed depended on the same demographic transitions, i.e. those including local recruitment (local production of new individuals), but not on the persistence of seeds in the seed bank. Therefore, plant sterilisation would be more efficient to limit feral population spread than selection of cultivars without seed dormancy The assumptions made about habitat continuity and homogeneity were consistent in the framework of this stepwise approach. However, integrating habitat heterogeneity and stochasticity would improve this invasion model. (c) 2005 Elsevier B.V All rights reserved.

Gaskell, G., A. Allansdottir, et al. (2006). Europeans and biotechnology in 2005: Patterns and trends: 1-86.

This is the sixth in a series of Eurobarometer surveys on biotechnology. The surveys have been conducted in 1991, 1993, 1996, 1999, 2002 and 2005. The survey is based on a representative sample of 25,000 respondents, approximately 1,000 in each EU Member State. Currently, issues such as stem cell research, the co-existence of GM, conventional and organic farming, the use of genetic information, and other innovations such as nanotechnology and pharmacogenetics are under discussion. Furthermore debates about broader issues such as the governance of science and citizen engagement continue. This survey stands as a contribution to the informed public and policy debate.

Gaskell, G., N. Allum, et al. (2004). "GM foods and the misperception of risk perception." Risk Anal JT - Risk analysis : an official publication of the Society for Risk Analysis. 24(1): 185-194.

Public opposition to genetically modified (GM) food and crops is widely interpreted as the result of the public's misperception of the risks. With scientific assessment pointing to no unique risks from GM crops and foods, a strategy of accurate risk communication from trusted sources has been advocated. This is based on the assumption that the benefits of GM crops and foods are self-evident. Informed by the interpretation of some qualitative interviews with lay people, we use data from the Eurobarometer survey on biotechnology to explore the hypothesis that it is not so much the perception of risks as the absence of benefits that is the basis of the widespread rejection of GM foods and crops by the European public. Some respondents perceive both risks and benefits, and may be trading off these attributes along the lines of a rational choice model. However, for others, one attribute-benefit-appears to dominate their judgments: the lexicographic heuristic. For these respondents, their perception of risk is of limited importance in the formation of attitudes toward GM food and crops. The implication is that the absence of perceived benefits from GM foods and crops calls into question the relevance of risk communication strategies for bringing about change in public opinion.

Gaugitsch, H. (2002). "Experience with environmental issues in GM crop production and the likely future scenarios." Toxicol Lett 127(1-3): 351-357.

In the Cartagena Protocol on Biosafety, standards for risk assessment of genetically modified organisms (GMOs) have been set. The criteria and information basis for the risk assessment of GMOs have been modified by the EU Directive 2001/18/EC. Various approaches to further improve the criteria for environmental risk assessment of GMOs are described in this study. Reports on the ecological impacts of the cultivation of certain non-transgenic crop plants with novel or improved traits as analogy models to transgenic plants showed that the effects of agricultural practice can be at least equally important as the effects of gene transfer and invasiveness, although the latter currently play a major role in risk assessment of transgenic crops. Based on these results the applicability of the methodology of 'Life Cycle Analysis (LCA)' for genetically modified plants in comparison with conventionally bred and organically grown crop plants was evaluated. The methodology was regarded as applicable with some necessary future improvements. In current projects, the assessment of toxicology and allergenicity of GM crops are analysed, and suggestions for standardization are developed. Based on results and recommendations from these efforts there are still the challenges of how to operationalize the precautionary principle and how to take into account ecologically sensitive ecosystems, including centres of origin and centres of genetic diversity.

Ge, Y., X. Cheng, et al. (2007). "Generation of transgenic Lolium temulentum plants by Agrobacterium tumefaciens-mediated transformation." Plant Cell Rep 26(6): 783-789.

Lolium temulentum L. (Darnel ryegrass) has been proposed to be used as a model species for functional genomics studies in forage and turf grasses, because it is a self-fertile, diploid species with a short life cycle and is closely related to other grasses. Embryogenic calluses were induced from mature embryos of a double haploid line developed through anther culture. The calluses were broken up into small pieces and used for Agrobacterium tumefaciens-mediated transformation. A. tumefaciens strain EHA105 harboring pCAMBIA1301 and pCAMBIA1305.2 vectors were used to infect embryogenic callus pieces. Hygromycin was used as a selection agent in stable transformation experiments. Hygromycin resistant calluses were obtained after 4-6 weeks of selection and transgenic plants were produced in 10-13 weeks after Agrobacterium-mediated transformation. Fertile plants were readily obtained after transferring the transgenics to the greenhouse. Transgenic nature of the regenerated plants was demonstrated by Polymerase chain reaction (PCR), Southern hybridization analysis, and GUS staining. Progeny analysis showed Mendelian inheritance of the transgenes. The transformation system provides a valuable tool for functionality tests of candidate genes in forage and turf grasses.

Genissel, A., F. Viard, et al. (2000). "Population genetics of Chrysomela tremulae: a first step towards management of transgenic Bacillus thuringiensis poplars Populus tremula X P-tremuloides." Hereditas 133(2): 85-93.

Many strategies have been proposed for delaying the development of insect resistance to Bacillus thuringiensis (Bt). The current paradigm for Bt resistance management is the high dose- refuge strategy. For this strategy to be successful: (i) heterozygotes must be killed in treated areas, (ii) resistant alleles must be rare (frequency < 10-3), and (iii) there must be a high level of gene flow between populations to ensure random mating. We studied gene flow within and between populations with a view to managing the resistance of Chrysomela tremulae (Coleoptera: Chrysomelidae) to new transgenic, highly toxic poplars expressing a synthetic Br gene. In this study, we assessed the extent of gene flow in C. tremulae within and between 16 sites in France and Belgium, using allozyme markers. We found a high level of genetic variability in C, tremulae, with a mean of 0.206<plus/minus>0.16. There were no obvious limitations to gene flow between populations of C. tremulae over large geographical distances (several hundreds of kilometres). Nevertheless, a very low level of genetic differentiation was observed between a site located in the south of France and the sampled sites from the Centre region.

Gepts, P. and R. Papa (2003). "Possible effects of (trans)gene flow from crops on the genetic diversity from landraces and wild relatives." Environ Biosafety Res 2(2): 89-103.

Gene flow is a potential concern associated with the use of transgenic crops because it could affect genetic diversity of related landraces and wild relatives. This concern has taken on added importance with the looming introduction of transgenic crops in centers of crop domestication (Mexico, China) and those producing pharmaceutical compounds. For gene flow to take place among cultivars and their wild relatives, several steps have to be fulfilled, including the presence of cultivars or wild relatives within pollen or seed dispersal range, the ability to produce viable and fertile hybrids, at least partial overlap in flowering time, actual gene flow by pollen or seed, and the establishment of crop genes in the domesticated or wild recipient populations. In contrast with domestication genes, which often make crops less adapted to natural ecosystems, transgenes frequently represent gains of function, which might release wild relatives from constraints that limit their fitness. In most sexually reproducing organisms, the chromosomal region affected by selection of a single gene amounts to a small percentage of the total genome size. Because of gene flow, the level of genetic diversity present in the domesticated gene pool becomes a crucial factor affecting the genetic diversity of the wild gene pool. For some crops, such as cotton and maize, the introduction of transgenic technologies has led to a consolidation of the seed industry and a reduction in the diversity of the elite crop gene pool. Thus, diversity in improved varieties grown by farmers needs to be monitored. Several areas deserve further study, such as the actual magnitude of gene flow and its determinants in different agroecosystems, the long-term effects of gene flow on genetic diversity both across gene pools and within genomes, the expression of transgenes in new genetic backgrounds, and the effects of socio-economic factors on genetic diversity.

Gianessi, L. P. (2005). "Economic and herbicide use impacts of glyphosate-resistant crops." Pest Manag Sci JT - Pest management science. 61(3): 241-245.

More than 95% of United States maize, cotton, soybean and sugarbeet acres are treated with herbicides for weed control. These products are used to improve the economic profitability of crop production for farmers. Since their introduction in 1996, over 75 million acres of genetically engineered glyphosate-resistant crops have been planted, making up 80% of soybean acres and 70% of cotton acres in the USA. These genetically engineered crops have been adopted by farmers because they are perceived to offer greater economic benefits than conventional crop and herbicide programs. The adoption of glyphosate-resistant crops has saved US farmers 1.2 billion dollars associated with the costs of conventional herbicide purchases, application, tillage and hand weeding. With the adoption of glyphosate-resistant sugarbeets on currently planted sugarbeet acres, US growers could potentially save an additional 93 million dollars. The adoption of glyphosate-resistant crops by US agriculture has reduced herbicide use by 37.5 million lbs, although the adoption of glyphosate-resistant sugarbeets would dampen this reduction by 1 million lbs.

Giddings, G. (1998). "Tansley Review No. 99 - The release of genetically engineered micro-organisms and viruses into the environment." New Phytologist 140(2): 173-184.

This review considers the reasons for, and research governing, the regulation and monitoring of genetically engineered micro- organisms and viruses (GEMs) released into the environment. The hazards associated with releasing GEMs into the environment are the creation and evolution of new pests and diseases, and damage to the ecosystem and non target species. The similarities and differences between GEMs and conventional microorganisms are discussed in relation to risk assessment. Other issues covered-include the persistence of microorganisms in the environment, transgene dispersal to non-engineered microbes and other organisms, the effects of transgenes and transformation on fitness, and the evolution of pests and pathogens that are given or acquire transgenes. Areas requiring further research are identified and recommendations for risk assessment made.

Giddings, G. (2000). "Modelling the spread of pollen from Lolium perenne. The implications for the release of wind-pollinated transgenics." Theoretical and Applied Genetics 100(6): 971-974.

The dispersal of pollen from a Lolium perenne source has previously been described using various Gaussian plume models which take distance and wind direction into account. One of these models is used here to calculate, using integration, possible pollen deposition onto small conspecific populations a kilometer from the source. The percentage of immigrant pollen is compared for six different sets of parameter values previously estimated from pollen-dispersal experiments. The source size is then scaled up to simulate what might happen if transgenic ryegrass was grown on a large scale. In this case it is seen that small conspecific populations might, in some conditions, be swamped by immigrant pollen, even if they are not directly downwind of the source. The implications of this are discussed in terms of assessing and managing the risks of releasing wind-pollinated transgenic crops.

Giddings, G. D., N. R. S. Hamilton, et al. (1997). "The release of genetically modified grasses .1. Pollen dispersal to traps in Lolium perenne." Theoretical and Applied Genetics 94(8): 1000-1006.

As part of a series of experiments on determining the risk of introducing genetically modified wind-pollinated forage grasses an experiment on pollen dispersal was conducted and-the use of theoretical descriptions to predict dispersal in model systems investigated. Pollen traps were placed around a central source of Lolium perenne. Traps were exposed with their sticky surfaces towards and away from the pollen source and also facing skywards during four stages of anthesis (early, mid 1, mid 2 and late). There was a great deal of variation in dispersal over time and to traps of different orientations. Twelve datasets were collected and used to comprehensively test Bateman's equations for the wind dispersal of pollen. The equations were not particularly useful for describing dispersal over distance and clearly need to be modified to take factors such as wind direction into account.

Giovannetti, M., C. Sbrana, et al. (2005). "The impact of genetically modified crops on soil microbial communities." Riv Biol 98(3): 393-417.

Genetically modified (GM) plants represent a potential benefit for environmentally friendly agriculture and human health. Though, poor knowledge is available on potential hazards posed by unintended modifications occurring during genetic manipulation. The increasing amount of reports on ecological risks and benefits of GM plants stresses the need for experimental works aimed at evaluating the impact of GM crops on natural and agro-ecosystems. Major environmental risks associated with GM crops include their potential impact on non-target soil microorganisms playing a fundamental role in crop residues degradation and in biogeochemical cycles. Recent works assessed the effects of GM crops on soil microbial communities on the basis of case-by-case studies, using multimodal experimental approaches involving different target and non-target organisms. Experimental evidences discussed in this review confirm that a precautionary approach should be adopted, by taking into account the risks associated with the unpredictability of transformation events, of their pleiotropic effects and of the fate of transgenes in natural and agro-ecosystems, weighing benefits against costs.

Goodman, R. E., S. L. Hefle, et al. (2005). "Assessing genetically modified crops to minimize the risk of increased food allergy: a review." Int Arch Allergy Immunol 137(2): 153-166.

The first genetically modified (GM) crops approved for food use (tomato and soybean) were evaluated for safety by the United States Food and Drug Administration prior to commercial production. Among other factors, those products and all additional GM crops that have been grown commercially have been evaluated for potential increases in allergenic properties using methods that are consistent with the current understanding of food allergens and knowledge regarding the prediction of allergenic activity. Although there have been refinements, the key aspects of the evaluation have not changed. The allergenic properties of the gene donor and the host (recipient) organisms are considered in determining the appropriate testing strategy. The amino acid sequence of the encoded protein is compared to all known allergens to determine whether the protein is a known allergen or is sufficiently similar to any known allergen to indicate an increased probability of allergic cross-reactivity. Stability of the protein in the presence of acid with the stomach protease pepsin is tested as a risk factor for food allergenicity. In vitro or in vivo human IgE binding are tested when appropriate, if the gene donor is an allergen or the sequence of the protein is similar to an allergen. Serum donors and skin test subjects are selected based on their proven allergic responses to the gene donor or to material containing the allergen that was matched in sequence. While some scientists and regulators have suggested using animal models, performing broadly targeted serum IgE testing or extensive pre- or post-market clinical tests, current evidence does not support these tests as being predictive or practical. Based on the evidence to date, the current assessment process has worked well to prevent the unintended introduction of allergens in commercial GM crops.

Graef, F., W. Zughart, et al. (2005). "Methodological scheme for designing the monitoring of genetically modified crops at the regional scale." Environ Monit Assess 111(1-3): 1-26.

According to EC regulations the deliberate release of genetically modified (GM) crops into the agro-environment needs to be accompanied by environmental monitoring to detect potential adverse effects, e.g. unacceptable levels of gene flow from GM to non-GM crops, or adverse effects on single species or species groups thus reducing biodiversity. There is, however, considerable scientific and public debate on how GM crops should be monitored with sufficient accuracy, discussing questions of potential adverse effects, agro-environmental variables or indicators to be monitored and respective detection methods; Another basic component, the appropriate number and location of monitoring sites, is hardly considered. Currently, no consistent GM crop monitoring approach combines these components systematically. This study focuses on and integrates spatial agro-environmental aspects at a landscape level in order to design monitoring networks. Based on examples of environmental variables associated with the cropping of Bt-Maize (Zea maize L.), herbicide-tolerant (HT) winter oilseed rape (Brassica napus L.), HT sugar beet (Beta vulgaris L.), and starch-modified potato (Solanum tuberosum L.), we develop a transferable framework and assessment scheme that comprises anticipated adverse environmental effects, variables to be measured and monitoring methods.These we integrate with a rule-based GIS (geographic information system) analysis, applying widely available spatial area and point information from existing environmental networks. This is used to develop scenarios with optimised regional GM crop monitoring networks.

Gregory, P., G. Hamilton, et al. (2006). "Vulnerability Assessment of New Jersey's Food Supply to Invasive Species: The New Jersey Import Project." New Solut 16(3): 289-299.

The United States' environment and economy have been severely impacted by unintentionally introduced biological organisms for the last 100 years. Our ecosystems and biological reserves of conservation importance are regularly invaded by non-indigenous species. To help prevent future invaders from entering the ports, this project undertaken at the Port of Elizabeth proposed to: 1. Catalog the different vegetable and fruit crops entering this country; 2. Evaluate the potential risk to New Jersey crops that an introduced exoticpest might pose; and 3. Evaluate the potential that imported crops entering the U.S. have for harboring exotic pests. The New Jersey IMPORT report, or Invasive Management Promoting Open and Responsible Trade project [1], details a newly designed ecological risk assessment tool to evaluate entry potential of invasive pests at the Port of Elizabeth. Risk designations were assigned to shipments of four fruits; seven vegetables; and two field/forage crops based on: i) Country of origin; ii) Amounts of commodities imported; and iii) Endemic pests present in exporting countries. Between 5,000 and 180,000 tons of crops were imported into the Port of Elizabeth from October 2001 to 2003. Pest risk analyses were drafted for twenty-five intercepted insects taken from the Port Information Network. In addition, eighteen pest risk analyses were drafted for invasive fungi, bacteria, and viruses of global concern as alerted by ProMed Digest. It was concluded that three crops imported remain at high risk: apples, peppers, and tomatoes. Peaches, soybeans, lettuce, sweet corn, potatoes, squash, and eggplant imported were considered moderate risk. Blueberries, cranberries, and alfalfa were considered low risk.

Gressel, J. and A. A. Levy (2006). "Agriculture: the selector of improbable mutations." Proc Natl Acad Sci U S A 103(33): 12215-12216.

Groot, A. T. and M. Dicke (2002). "Insect-resistant transgenic plants in a multi-trophic context." The Plant Journal 31(4): 387-406.

So far, genetic engineering of plants in the context of insect pest control has involved insertion of genes that code for toxins, and may be characterized as the incorporation of biopesticides into classical plant breeding. In the context of pesticide usage in pest control, natural enemies of herbivores have received increasing attention, because carnivorous arthropods are an important component of insect pest control. However, in plant breeding programmes, natural enemies of herbivores have largely been ignored, although there are many examples that show that plant breeding affects the effectiveness of biological control. Negative influences of modified plant characteristics on carnivorous arthropods may induce population growth of new, even more harmful pest species that had no pest status prior to the pesticide treatment. Sustainable pest management will only be possible when negative effects on non-target, beneficial arthropods are minimized. In this review, we summarize the effects of insect-resistant crops and insect-resistant transgenic crops, especially Bt crops, from a food web perspective. As food web components, we distinguish target herbivores, non-target herbivores, pollinators, parasitoids and predators. Below-ground organisms such as Collembola, nematodes and earthworms should also be included in risk assessment studies, but have received little attention. The toxins produced in Bt plants retain their toxicity when bound to the soil, so accumulation of these toxins is likely to occur. Earthworms ingest the bound toxins but are not affected by them. However, earthworms may function as intermediaries through which the toxins are passed on to other trophic levels. In studies where effects of insect-resistant (Bt) plants on natural enemies were considered, positive, negative and no effects have been found. So far, most studies have concentrated on natural enemies of target herbivores. However, Bt toxins are structurally rearranged when they bind to midgut receptors, so that they are likely to lose their toxicity inside target herbivores. What happens to the toxins in non-target herbivores, and whether these herbivores may act as intermediaries through which the toxins may be passed on to the natural enemies, remains to be studied.

Guadagnuolo, R., J. Clegg, et al. (2006). "Relative fitness of transgenic vs. non-transgenic maize x teosinte hybrids: a field evaluation." Ecol Appl 16(5): 1967-1974.

Concern has been often expressed regarding the impact and persistence of transgenes that enter wild populations via gene flow. The impact of a transgene and its persistence are largely determined by the relative fitness of transgenic hybrids and hybrid derivatives compared to non-transgenic plants. Nevertheless, few studies have addressed this question experimentally in the field. Despite the economic importance of maize, and the fact that it naturally hybridizes with the teosinte taxon Zea mays ssp. mexicana, sometimes known as "chalco teosinte," the question has received little experimental attention in this system. Using a glyphosate-tolerant maize cultivar and chalco teosinte as parental lines, we carried out a field experiment testing (1) the relative fitness of maize x teosinte hybrids, compared to their parental taxa, as well as (2) the relative fitness of transgenic hybrids compared to non-transgenic hybrids created from the same parental stock. In order to evaluate the influence of the transgenic construct in different genetic backgrounds, our study included transgenic and non-transgenic pure maize progeny from the cultivar as well. We measured both vegetative and reproductive parameters. Our results demonstrated that hybrids have greater vigor and produced more seeds than the wild parent. However, in the absence of selective pressure from glyphosate herbicide, we did not observe any direct positive or negative impact of the transgene on the fitness or vigor of either the hybrids or pure maize progeny. We discuss our results in terms of the potential for spontaneous transgene flow and introgression from transgenic maize into sympatric teosinte.

Guadagnuolo, R., D. Savova-Bianchi, et al. (2001). "Search for evidence of introgression of wheat (Triticum aestivum L.) traits into sea barley (Hordeum marinum s.str. Huds.) and bearded wheatgrass (Elymus caninus L.) in central and northern Europe, using isozymes, RAPD and microsatellite markers." Theoretical and Applied Genetics 103(2-3): 191-196.

Seeds of English and Austrian populations of bearded wheatgrass (Elymus caninus L.) and sea barley (Hordeum marinum Huds.) growing in the vicinity of wheat (Triticum aestivum L.) fields were collected in order to search for evidence of the introgression of wheat traits into these wild relatives. Seeds were sown and plants grown for subsequent analyses using morphological and genetic (isozymes, RAPD and wheat microsatellites) markers. No F-1 hybrids were found within the individuals of the two species grown, neither with morphological nor with genetic markers. Also, no evidence of introgression of wheat traits into E. caninus was observed. However, in one individual of H. marinum which had the typical morphology of this species, numerous species-specific DNA markers of wheat were amplified, thereby demonstrating previous hybridization. Consequently, the hybridization between wheat and H. marinum under natural conditions and the introgression of wheat traits into this wild relative seems to be possible. Our results contribute to the risk assessment of transgenic wheat cultivation.

Gueritaine, G., S. Bazot, et al. (2003). "Emergence and growth of hybrids between Brassica napus and Raphanus raphanistrum." New Phytologist 158(3): 561-567.

Risk assessment studies of transgenic crops have recently brought evidence of a low spontaneous hybridization frequency of Brassica napus with Raphanus raphanistrum . The fate of the first generation hybrids is crucial to determine the initial rate of spread of transgenes.This work aims to compare the fitness components of parents and F-1 hybrids at the first step of the life cycle. The ability to emerge, establish seedling, cover the soil and develop adult plant was examined in controlled and field conditions, alone or in competition.The F-1 hybrids showed a lower seedling emergence, a significant delay of emergence, and a lower survival than for both parents. Rosette diameter and dry matter of hybrid plants were very reduced compared with those of both parents, especially when they grew in the field and under competition conditions.The relevance of these results to gene flow and possible impact to agriculture and environment is discussed.

Gueritaine, G., M. Sester, et al. (2002). "Fitness of backcross six of hybrids between transgenic oilseed rape (Brassica napus) and wild radish (Raphanus raphanistrum)." Molecular Ecology 11(8): 1419-1426.

The process of introgression between a transgenic crop modified for better agronomic characters and a wild relative could lead potentially to increased weediness and adaptation to the environment of the wild species. However, the formation of hybrid and hybrid progeny could be associated with functional imbalance and low fitness, which reduces the risk of gene escape and establishment of the wild species in the field. Our work compares the fitness components of parents and different types of backcross in the sixth generation of hybrids between transgenic oilseed rape (Brassica napus , AACC, 2n = 38) resistant to the herbicide glufosinate and wild radish (Raphanus raphanistrum, RrRr, 2n = 18). The backcross with oilseed rape cytoplasm (OBC) has a fitness value 100 times lower than that of the backcross with wild radish cytoplasm (RBC). The herbicide-resistant RBC has similar growth to the susceptible RBC, but final male and female fitness values are two times lower. In turn, susceptible RBC exhibit similar fitness to the control wild radishes. The relative fitnesses of the different types are the same whether or not they grow under competitive conditions. The consequence on fitness of the chromosome location of the transgene conferring resistance and the relevance of these results to the impact of gene flow on the environment are discussed.

Gurian-Sherman, D. (2003). "Risks of genetically engineered crops." Science 301(5641): 1845-.

Gurian-Sherman, D. (2006). Contaminating the wild? Gene flow from experimental field trials of genetically engineered crops to related wild plants, Center for Food Safety: 51.

Hails, R. S. and K. Morley (2005). "Genes invading new populations: a risk assessment perspective." Trends Ecol Evol 20(5): 245-252.

One of the concerns raised over the introduction of genetically modified crops is that transgenes will invade populations of wild relatives, causing ecologically significant changes in fitness. In recent years, this has given rise to several studies estimating hybridization rates and the fitness of crop-wild relative hybrids. These studies have established that transgenes are likely to move to F1 hybrids, albeit at low frequency. Hybridization, however, is not synonymous with introgression, and questions remain as to whether particular transgenes will cause ecologically significant changes in recipient plant populations. Research effort should now focus on estimating any changes in the fitness of a population as a consequence of having a transgene, understanding genotype x environment interactions, and deducing the extent to which pathogens and herbivores (transgene targets) regulate wild relative populations. This will involve a combination of manipulative experiments and empirically motivated mathematical models.

Halfhill, M. D., B. Zhu, et al. (2004). "Hybridization and backcrossing between transgenic oilseed rape and two related weed species under field conditions." Environ Biosafety Res 3(2): 73-81.

Determining the frequency of crop-wild transgene flow under field conditions is a necessity for the development of regulatory strategies to manage transgenic hybrids. Gene flow of green fluorescent protein (GFP) and Bacillus thuringiensis (Bt) transgenes was quantified in three field experiments using eleven independent transformed Brassica napus L. lines and the wild relatives, B. rapa L. and Raphanus raphanistrum L. Under a high crop to wild relative ratio (600:1), hybridization frequency with B. rapa differed among the individual transformed B. napus lines (ranging from ca. 4% to 22%), however, this difference could be caused by the insertion events or other factors, e.g., differences in the hybridization frequencies among the B. rapa plants. The average hybridization frequency over all transformed lines was close to 10%. No hybridization with R. raphanistrum was detected. Under a lower crop to wild relative ratio (180:1), hybridization frequency with B. rapa was consistent among the transformed B. napus lines at ca. 2%. Interspecific hybridization was higher when B. rapa occurred within the B. napus plot (ca. 37.2%) compared with plot margins (ca. 5.2%). No significant differences were detected among marginal plants grown at 1, 2, and 3 m from the field plot. Transgene backcrossing frequency between B. rapa and transgenic hybrids was determined in two field experiments in which the wild relative to transgenic hybrid ratio was 5-15 plants of B. rapa to 1 transgenic hybrid. As expected, ca. 50% of the seeds produced were transgenic backcrosses when the transgenic hybrid plants served as the maternal parent. When B. rapa plants served as the maternal parent, transgene backcrossing frequencies were 0.088% and 0.060%. Results show that transgene flow from many independent transformed lines of B. napus to B. rapa can occur under a range of field conditions, and that transgenic hybrids have a high potential to produce transgenic seeds in backcrosses.

Halford, N. G. (2004). "Prospects for genetically modified crops." Annals of Applied Biology 145(1): 17-24.

Genetically modified (GM) crops have been in use commercially around the world for almost a decade. This review covers the successes and failures of GM crop varieties in that time, the current status of GM crop adoption and the traits that are being used. It also describes some of the GM crops that might come on to the market in the next decade. The barriers in the way of GM crop development in Europe, including consumer hostility, the difficulty in gaining official approval and discriminatory labelling laws are discussed.

Hallman, W. K. and S. C. Condry (2006). Public opinion and media coverage of animal cloning and the food supply: Executive Summary. New Brunswick, NJ, Food Policy Institute, Rutgers: 1-5.

As part of its research program examining public knowledge, attitudes and opinions about food biotechnology, the Food Policy Institute recently completed a project examining public opinions about animal cloning and the products of animal cloning in the food supply. The project consisted of three components: 1) a review of the publicly available surveys of public opinion related to the issue; 2) a set of interviews with a group of opinion leaders looking at their mental models of animal cloning and the food supply; and, 3) an examination of media coverage of cloning and animals on websites, in news stories on the Internet, and in American print news stories published in 2005. The purpose of the study was to examine the intersection of rhetoric and opinion regarding the controversial issues related to animals, cloning, and the food supply.

Hancock, J. F. (2003). "A framework for assessing the risk of transgenic crops." Bioscience.

Hansen, L. B., H. R. Siegismund, et al. (2001). "Introgression between oilseed rape (Brassica napus L.) and its weedy relative B-rapa L. in a natural population." Genetic Resources and Crop Evolution 48(6): 621-627.

We investigated introgression in a mixed weedy population of oilseed rape (Brassica napus) and its relative B. rapa using species-specific AFLP-markers. The population was situated in a field relayed from conventional to organic cultivation 11 years ago. One-hundred-and-two B. napus or B. rapa-like plants were collected in a 3 m(2) plot. Of these, one was a first generation hybrid (F-1) and nearly half (44 plants) were introgressed, having both B. napus and B. rapa specific markers. The remaining plants apparently corresponded to pure species, with 50 having only B. rapa- and seven having only B. napus-specific markers. We compared the number of markers in the plants from the weedy population with the numbers in controlled backcross generations (BC1 and BC2). The marker distribution in the weedy population resembled the distribution in the second backcross generation most closely. Together with the cultivation history of the field. this suggests that the introgression process in the weedy mixed population has been in progress for some time. This study is the first to show introgression between B. napus and B. rapa under natural conditions.

Harwood, J. D., W. G. Wallin, et al. (2005). "Uptake of Bt endotoxins by nontarget herbivores and higher order arthropod predators: molecular evidence from a transgenic corn agroecosystem." Mol Ecol 14(9): 2815-2823.

The planting of transgenic crops expressing Bacillus thuringiensis endotoxins is widespread throughout the world; the prolific increase in their application exposes nontarget organisms to toxins designed to control pests. To date, studies have focused upon the effects of Bt endotoxins on specific herbivores and detritivores, without consideration of their persistence within arthropod food webs. Here, we report the first quantitative field evaluation of levels of Bt endotoxin within nontarget herbivores and the uptake by higher order arthropods. Antibody-based assays indicated significant quantities of detectable Cry1Ab endotoxin within nontarget herbivores which feed on transgenic corn (including the corn flea beetle, Chaetocnema pulicaria, Japanese beetle, Popillia japonica and southern corn rootworm, Diabrotica undecimpunctata howardi). Furthermore, arthropod predators (Coccinellidae, Araneae, and Nabidae) collected from these agroecosystems also contained significant quantities of Cry1Ab endotoxin indicating its movement into higher trophic levels. This uptake by predators is likely to have occurred by direct feeding on plant material (in predators which are facultatively phytophagous) or the consumption of arthropod prey which contained these proteins. These data indicate that long-term exposure to insecticidal toxins occurs in the field. These levels of exposure should therefore be considered during future risk assessments of transgenic crops to nontarget herbivores and arthropod predators.

Haslberger, A. G. (2006). "Need for an "integrated safety assessment" of GMOs, linking food safety and environmental considerations." J Agric Food Chem 54(9): 3173-3180.

Evidence for substantial environmental influences on health and food safety comes from work with environmental health indicators which show that agroenvironmental practices have direct and indirect effects on human health, concluding that "the quality of the environment influences the quality and safety of foods" [Fennema, O. Environ. Health Perspect. 1990, 86, 229-232). In the field of genetically modified organisms (GMOs), Codex principles have been established for the assessment of GM food safety and the Cartagena Protocol on Biosafety outlines international principles for an environmental assessment of living modified organisms. Both concepts also contain starting points for an assessment of health/food safety effects of GMOs in cases when the environment is involved in the chain of events that could lead to hazards. The environment can act as a route of unintentional entry of GMOs into the food supply, such as in the case of gene flow via pollen or seeds from GM crops, but the environment can also be involved in changes of GMO-induced agricultural practices with relevance for health/food safety. Examples for this include potential regional changes of pesticide uses and reduction in pesticide poisonings resulting from the use of Bt crops or influences on immune responses via cross-reactivity. Clearly, modern methods of biotechnology in breeding are involved in the reasons behind the rapid reduction of local varieties in agrodiversity, which constitute an identified hazard for food safety and food security. The health/food safety assessment of GM foods in cases when the environment is involved needs to be informed by data from environmental assessment. Such data might be especially important for hazard identification and exposure assessment. International organizations working in these areas will very likely be needed to initiate and enable cooperation between those institutions responsible for the different assessments, as well as for exchange and analysis of information. An integrated assessment might help to focus and save capacities in highly technical areas such as molecular characterization or profiling, which are often necessary for both assessments. In the area of establishing international standards for traded foods, such as for the newly created Standards in Trade and Development Facility (STDF), an integrated assessment might help in the consideration of important environmental aspects involved in health and food safety. Furthermore, an established integrated view on GMOs may create greater consumer confidence in the technology.

Hayes, K. R., P. C. Gregg, et al. (2004). "Identifying hazards in complex ecological systems. Part 3: Hierarchical Holographic Model for herbicide tolerant oilseed rape." Environ Biosafety Res 3(2): 109-128.

This paper is the third in a series designed to demonstrate the application of rigorous, systematic hazard identification techniques to ecological systems. Here we use Hierarchical Holographic Modelling to identify the potential ecological hazards associated with the commercial release of herbicide tolerant oilseed rape. Hierarchical Holographic Models decompose complex systems into a series of sub-systems and consider interactions between the components and processes of these sub-systems in order to identify hazards. In this example we considered 1356 potential interactions between the biological, chemical and physical components and processes of the herbicide tolerant oilseed rape environment, and identified 152 potential hazards, grouped into 14 categories. The hazards were subsequently scored for degree of concern and plausibility, and then compared with an equivalent list of hazards generated independently by a checklist approach. The incidence of herbicide tolerant volunteers (and weeds) both on and off the farm had the highest average score of all the ecological hazard categories. The checklist based approach identified or implied 44% of the hazards identified in the Hierarchical Holographic Model, including nine of the ten hazards ranked most important. The checklist approach focussed almost exclusively on the phenotypic and genotypic hazards associated with herbicide tolerant oilseed rape and largely ignored the hazards associated with the circumstances surrounding its use. As a result the checklist identified only 6 out of the 79 potential hazards associated with changes to farming practice. The commercial release of herbicide tolerant oilseed rape will be associated with changes in tillage and the application of post-emergent herbicides. It may also lead to changes in spray schedules of insecticide and fungicide. Many of the environmental hazards identified with these changes are plausible and may warrant further investigation or targeted monitoring.

Haygood, R., A. R. Ives, et al. (2003). "Consequences of recurrent gene flow from crops to wild relatives." Proc Biol Sci 270(1527): 1879-1886.

Concern about gene flow from crops to wild relatives has become widespread with the increasing cultivation of transgenic crops. Possible consequences of such gene flow include genetic assimilation, wherein crop genes replace wild ones, and demographic swamping, wherein hybrids are less fertile than their wild parents, and wild populations shrink. Using mathematical models of a wild population recurrently receiving pollen from a genetically fixed crop, we find that the conditions for genetic assimilation are not stringent, and progress towards replacement can be fast, even for disfavoured crop genes. Demographic swamping and genetic drift relax the conditions for genetic assimilation and speed progress towards replacement. Genetic assimilation can involve thresholds and hysteresis, such that a small increase in immigration can lead to fixation of a disfavoured crop gene that had been maintained at a moderate frequency, even if the increase in immigration is cancelled before the gene fixes. Demographic swamping can give rise to 'migrational meltdown', such that a small increase in immigration can lead to not only fixation of a disfavoured crop gene but also drastic shrinkage of the wild population. These findings suggest that the spread of crop genes in wild populations should be monitored more closely.

Hegde, S. G., J. D. Nason, et al. (2006). "The evolution of California's wild radish has resulted in the extinction of its progenitors." Evolution Int J Org Evolution 60(6): 1187-1197.

If two previously isolated taxa mutually assimilate through hybridization and subsequent biparental introgression, and if their introgressed descendants have the same or higher fitness than their parents, then gene flow should result in the local extinction of parental taxa via replacement by hybrid derivatives. These dramatic events may occur rapidly, even in a few generations. Given the speed at which such extinction by hybridization may occur, it may be difficult to identify that the process has occurred. Thus, documented instances of extinction by hybridization are rare, and especially so for cases in which both parents are replaced by the hybrid lineage. Here we report morphological and allozyme evidence for the local extinction of two Raphanus species in California via replacement by their hybrid-derived descendants. The results from a greenhouse experiment demonstrate that California wild radishes have a specific combination of traits from their progenitors, and comparison of our results to that of an earlier report indicate that pure parental types are no longer present in the wild. Our results also show the hybrid-derived lineage has transgressive fruit weight compared to its parents. Allozyme analysis demonstrates that California wild radishes are derived from hybridization between the putative parental species. However, that analysis also demonstrates that California wild radish has now become an evolutionary entity separate from both of its parents. We suggest that the aggressive colonizing behavior of the hybrid-derived lineage probably results from a novel combination of parental traits, rather than genetic variability of the population per se.

Hegde, S. G. and J. G. Waines (2004). "Hybridization and Introgression between Bread Wheat and Wild and Weedy Relatives in North America." Crop Sci 44(4): 1145-1155.

Introgression between cultivars and wild relatives is common in several angiosperm taxa including the grass family Poaceae. Bread wheat (Triticum aestivum L.) is a domesticated allohexaploid species (genome formula BBAADD) without any known wild hexaploid relative in the genus Triticum. Bread wheat is also related to the genus Aegilops L., which has probably contributed two of the three genomes of bread wheat. A few tetraploid Aegilops species, including Ae. cylindrica Host. and Ae. triuncialis L., occur as weeds both in the Mediterranean basin and in West Asia. Introduced populations of these weeds are also known to occur in North America. These species have been known to introgress occasionally with bread wheat when grown near wheat fields. Similarly, rye (Secale cereale L.), a species from a distant genus, has a potential to introgress with bread wheat. A few natural introgressive hybrids between herbicide resistant wheat and Ae. cylindrica and between wheat and rye have been created or recovered in North America. Natural hybrids between wheat and Ae. triuncialis have not been observed in North America. The available data do not suggest the prevalence of large-scale introgression between bread wheat and its wild relatives in North America. Nevertheless, with modern bread wheat cultivars being developed with novel traits, such as herbicide and disease resistance, an in-depth evaluation of the extent and nature of introgression between weedy Aegilops or Secale species and bread wheat is useful both for assessing potential ecological risks that may be associated with trait presence in hybrids and for formulating strategies to manage gene transfer to hybrids. In this review, we discuss the existing literature on reproductive ecology of bread wheat and on introgression between bread wheat and its wild relatives in the genera Aegilops and Secale that occur in North America. We also discuss the implications of introgression in consideration of the current and possible future development of transgenic wheat.

Hellmich, R. L., B. D. Siegfried, et al. (2001). "Monarch larvae sensitivity to Bacillus thuringiensis- purified proteins and pollen." Proc Natl Acad Sci U S A 98(21): 11925-11930.

Laboratory tests were conducted to establish the relative toxicity of Bacillus thuringiensis (Bt) toxins and pollen from Bt corn to monarch larvae. Toxins tested included Cry1Ab, Cry1Ac, Cry9C, and Cry1F. Three methods were used: (i) purified toxins incorporated into artificial diet, (ii) pollen collected from Bt corn hybrids applied directly to milkweed leaf discs, and (iii) Bt pollen contaminated with corn tassel material applied directly to milkweed leaf discs. Bioassays of purified Bt toxins indicate that Cry9C and Cry1F proteins are relatively nontoxic to monarch first instars, whereas first instars are sensitive to Cry1Ab and Cry1Ac proteins. Older instars were 12 to 23 times less susceptible to Cry1Ab toxin compared with first instars. Pollen bioassays suggest that pollen contaminants, an artifact of pollen processing, can dramatically influence larval survival and weight gains and produce spurious results. The only transgenic corn pollen that consistently affected monarch larvae was from Cry1Ab event 176 hybrids, currently <2% corn planted and for which re-registration has not been applied. Results from the other types of Bt corn suggest that pollen from the Cry1Ab (events Bt11 and Mon810) and Cry1F, and experimental Cry9C hybrids, will have no acute effects on monarch butterfly larvae in field settings.

Herring, R. J. (2007). "The Genomics revolution and development studies: Science, poverty and politics." Journal of Development Studies 43(1): 1-30.

The genomics revolution in biology has enabled technologies with unprecedented potential; genetic engineering is changing the terrain of development studies. Societies have reacted with indifference or appreciation to genetically engineered pharmaceuticals, beginning with insulin; yet for food and agriculture, a globally contentious politics and unprecedented policy dilemmas have arisen. Transgenic organisms raise questions of property, ethics and safety unimaginable a generation ago: what can be owned and with what responsibility? Much turns on science: how one conceptualizes evidence, knowledge, uncertainty and risk. Both opponents and proponents of frontier applications in biotechnology have a poverty story to tell, but with divergent implications. The balance in this global debate has perceptibly shifted; a new developmentalist consensus concludes that the worlds poor may benefit from genetic engineering: the question is 'under what conditions'? This essay introduces a collection of scholarly treatments that begin with the needs of the poor - for income, nutrition, environmental integrity - and evaluate theory and evidence for contributions from transgenic crops. The new consensus assumes much about biosafety, bioproperty and biopolitics that is contrary to ground realities - the actual capacity of firms and states to monitor and control biotechnology - but raises new questions at the frontiers of development studies.

Herring, R. J. (2007). "Stealth seeds: Bioproperty, biosafety, biopolitics." Journal of Development Studies 43(1): 130-157.

Transgenic seeds in both India (Bt cotton) and Brazil (glyphosate-resistant soybeans) spread widely and rapidly through farming communities outside the reach of biosafety or bioproperty institutions. Stealth transgenies are saved, cross-bred, repackaged, sold, exchanged and planted in an anarchic agrarian capitalism that defies surveillance and control of firms and states. The outcome is more pro-poor than alternative modes of diffusion, but undermines a growing consensus in the international development community on appropriate biosafety and intellectual property institutions for biotechnology. Second, stealth procurement of biotechnology divides nominally pro-poor political coalitions, driven by a great ideational divide on uncertainties and risks of transgenics. The ability of seeds to move underground through stealth strategies of farmers undermines widely-assumed bio-safety-regime capability. Likewise, property in biotechnology appears less monopolistic and powerful, more relational and contingent. Stealth practices of farmers in pursuit of transgenics contrary to wishes of firms, states and many NGOs suggest a different model of the farmer than that often encountered in both developmentalist and anti-'GMO' discourse: more active, creative and autonomous, less hapless and supine. Resultant incapacity of social institutions to secure interests of firms and states in biotechnology renders more likely eventual development of controls from genetic engineering - the 'terminator technology' of political dramaturgy.

Hill, R. and C. Sendashonga (2006). "Conservation biology, genetically modified organisms, and the biosafety protocol." Conserv Biol 20(6): 1620-1625.

Concerns have been raised regarding the potential adverse effects on biological diversity of the use of living modified organisms (LMOs, which are commonly known by similar terms such as genetically modified organisms). At the international level these concerns are addressed in part by an agreement known as the Cartagena Protocol on Biosafety and include potential toxic effects of insect-resistant crops on nontarget organisms and potential ecological effects of gene flow from modified crops, fish, microorganisms, or insects to wild species or counterparts. We reviewed the protocol's main provisions, including those dealing with risk assessment and risk management, decision making on imports, documentation accompanying shipments, and liability resulting from damages caused by LMOs. A medium-term program of work has been adopted by the parties, which includes the potential contribution of conservation biologists to delivering capacity building, developing risk assessment guidance, evaluating mechanisms of potential ecological damages from LMOs, and other issues. Conservation biologists and other experts have opportunities to influence the negotiations and implementation of the protocol by providing inputs at meetings, offering expertise to governments and organizations, and participating in or developing relevant projects and initiatives. Involvement of conservation biologists in the implementation and further development of the protocol would contribute to its effectiveness.

Hills, M. J., L. Hall, et al. (2007). "Genetic use restriction technologies (GURTs): strategies to impede transgene movement." Trends in Plant Science 12(4): 177-183.

No clear consensus has emerged in the debate about the risks posed by transgenic crops and how to assess these risks accurately. In the meantime, interest is growing in strategies to impede transgene movement. This attention is being driven, in part, by expanding interest in using transgenic crops to produce pharmaceutical and industrial products. Potential strategies to impede transgene movement have been published in the scientific literature, and numerous patents have been submitted; however, the efficacy of such strategies has still to be evaluated in a field situation. In this review, we discuss some of the genetic strategies that could be used to restrict the spread of transgenes, although at present many of these technologies are still largely at a theoretical stage of development.

Holling, C. S. (2000). "Policy dialogue: Genetically modified organisms in agriculture." Conservation Ecology 4(4): 14.

Holms, R. and V. Erickson (2006). Genetically engineered creeping bentgrass briefing paper: Region 6, US Forest Service.

Hooftman, D. A. P., M. J. D. Jong, et al. (2007). "Modelling the long-term consequences of crop-wild relative hybridization: a case study using four generations of hybrids." Journal of Applied Ecology 44(5): 1035-1045.

1. Hybridization between crops and wild relatives seems possible for many crop taxa. Subsequent introgression of crop-specific traits into wild relatives might lead to the formation of introgressant populations. Until now, few studies have evaluated demographically fitness changes combined with empirically defined heterosis breakdown levels to assess the likelihood of such potential hybrid population formation. 2. For the establishment of case study data, we produced four generations of hybrids between the predominantly autogamous annuals Lactuca sativa (lettuce) and its wild relative L. serriola, along both the autogamous and backcross pathways. Seeds of parental and hybrid lineages were sown individually in field plots and monitored up to and including seed-set. 3. All four hybrid generations were phenotypically similar to L. serriola, but survival rates of hybrids in both pathways were significantly higher in early (1st and 2nd) hybrid generations. Combined with higher germination rates, this resulted in higher lambda s for all hybrid classes, relative to L. serriola. This fitness surplus decreases through the generations, which is interpreted as heterosis breakdown. 4. These data were entered in a stochastic model. In general, the likelihood of a rapid full displacement of L. serriola at realistic, i.e. low, outcrossing rates seems limited. More likely is the formation of a population containing a wide variety of genotypes with or without L. serriola included. 5. Synthesis and applications. We demonstrate a simple model for providing likelihood estimates for different scenarios of introgression consequences, with the potential to be used for risk assessment of new crops. When including estimates of heterosis breakdown in our predictions, the speed of displacement of the wild taxon is less dramatic than other modelling attempts suggest. Furthermore, although wild relative displacement is the most likely scenario, other outcomes are possible, including no displacement at all.

Hudson, L. C., D. Chamberlain, et al. (2001). "GFP-tagged pollen to monitor pollen flow of transgenic plants." Molecular Ecology Notes 1(4): 321-324.

In this study, the pollen-active LAT59 promoter from tomato was used to express a green fluorescent protein (GFP) encoding gene in Nicotiana tabacum (tobacco) pollen. This promoter is preferentially expressed in anthers and pollen. Pollen in transgenic plants segregated in a 1 : 1 Mendelian ratio, and the plants were polymerase chain reaction (PCR)-positive. GFP- tagged pollen was developed as a tool for tracking the movement of transgenic plant pollen in the environment. Specifically, it should be a useful tool for characterizing the spatial distribution patterns of transgenic pollen, to determine pollination mechanisms, to monitor the effects on nontarget organisms, and to monitor gene flow in field conditions.

Hudson, L. C., M. D. Halfhill, et al., Eds. (2005). Transgene dispersal through pollen. Methods Mol Biol. Totowa, NJ, Humana Press Incl.

Techniques used for the transfer of novel genes into host plant genomes have created new possibilities for crop improvement. The implementation of transgenic crop species into agriculture has introduced the possibility of transgene escape into the environment via pollen dispersal. Although the movement of pollen is a critical step in transgene escape, there is currently no system to monitor transgenic pollen movement under field conditions. The development of an effective in vivo monitoring system suitable for use under field conditions is needed for research and commercial purposes so potential risks can be quantified and evaluated. This chapter describes the development of a model system using green fluorescent protein (GFP) expression in pollen as a marker to monitor pollen distribution patterns. A pollen specific promoter was used to express the GFP gene in tobacco (Nicotiana tabacum L.). GFP was visualized in pollen and growing pollen tubes using fluorescent microscopy. Furthermore, the goal of this research was to compare the dynamics of pollen movement with that of gene flow by using another method of whole plant expression of GFP to estimate out-crossing frequencies by progeny analysis. Pollen movement and gene flow were quantified under field conditions. Pollen traps were collected and screened for presence of GFP-tagged pollen using fluorescence microscopy. Progeny from wild type plants were screened with a hand held ultraviolet light for detection of the GFP phenotype.

Ilardi, V. and M. Barba (2002). "Assessment of functional transgene flow in tomato fields." Molecular Breeding 8(4): 311-315.

As the flow of pollen-carrying transgenes is considered to be one of the main problems associated with the release of genetically modified plants, the impact on the environment of transgenic tomato plants highly resistant to cucumber mosaic virus (CMV) was evaluated. The frequency of spontaneous crossing between homozygous transgenic tomato, cv. UC82B, and untransformed controls was assessed in two Italian growing areas. Transformed plants expressed the CMV coat protein (CP), inducing resistance to the virus, and neomycin phosphotransferase II (NPTII), used as an in vitro selectable marker. For each field, a sample of at least 2000 progeny plants of the `wild-type' UC82B control was screened to search for `hybrids' expressing the transgenic proteins. Kanamycin sprayed on seedling leaves and DAS-ELISA were used to detect NPTII and CMV-CP, respectively. Plants expressing the transgenic proteins were then analysed by PCR using CMV-CP gene-specific primers. Two plants from each field were found to express the transgenes. These plants, however, proved to be homozygous for transgenes, indicating that they did not originate by cross-pollination between transgenic and `wild- type' parents, but probably derived from transgenic seeds that accidentally contaminated untransformed seed stocks during harvesting. These results show that under our conditions, no transgene flow was detected in cv. UC82B tomatoes in the two fields.

IUFRO. (2007). "IUFRO: Publications and references / Forests and Genetically Modified Trees / Task Forces." from http://www.iufro.org/science/task-forces/genetics/publications-and-references/

James, C. M., J. A. Barrett, et al. (2001). "A rapid PCR based method to establish the potential for paternal inheritance of chloroplasts in Pelargonium." Plant Molecular Biology Reporter 19(2): 163-167.

A simple procedure for the amplification of chloroplast DNA from pollen is described. This allows the potential for biparental or paternal inheritance of chloroplasts in angiosperms to be established rapidly and reliably. Such information is important when chloroplast DNA, which is generally assumed to be inherited maternally, is used to study gene flow or reconstruct phylogenies. The technique could also prove valuable in assessing the risks of transgene escape via pollen of genetically modified plants, in which the chloroplast genome rather than the nucleus has been transformed.

James, R. R., S. P. DiFazio, et al. (1998). "Environmental effects of genetically engineered woody biomass crops." Biomass and Bioenergy 14(4): 403-414.

Jansson, S. and C. J. Douglas (2007). "Populus: a model system for plant biology." Annu Rev Plant Biol 58: 435-458.

With the completion of the Populus trichocarpa genome sequence and the development of various genetic, genomic, and biochemical tools, Populus now offers many possibilities to study questions that cannot be as easily addressed in Arabidopsis and rice, the two prime model systems of plant biology and genomics. Tree-specific traits such as wood formation, long-term perennial growth, and seasonality are obvious areas of research, but research in other areas such as control of flowering, biotic interactions, and evolution of adaptive traits is enriched by adding a tree to the suite of model systems. Furthermore, the reproductive biology of Populus (a dioeceous wind-pollinated long-lived tree) offers both new possibilities and challenges in the study and analysis of natural genetic and phenotypic variation. The relatively close phylogenetic relationship of Populus to Arabidopsis in the Eurosid clade of Eudicotyledonous plants aids in comparative functional studies and comparative genomics, and has the potential to greatly facilitate studies on genome and gene family evolution in eudicots.

Jenczewski, E., J. M. Prosperi, et al. (1999). "Evidence for gene flow between wild and cultivated Medicago sativa (Leguminosae) based on allozyme markers and quantitative traits." American Journal of Botany 86(5): 677-687.

Genetic differentiation between co-occurring crops and their wild relatives will be greatly modified by crop-to-weed gene flow and variation between human and natural selective pressures. The maintenance of original morphological features in most natural populations of Medicago sativa in Spain questions the relative extent of these antagonistic forces. In this paper, we measured and compared the pattern of population differentiation within and among the wild and cultivated gene pool with respect to both allozymes and quantitative traits. Patterns of diversity defined three kinds of natural populations. First, some populations were intermediate with respect to both allozymes and quantitative traits. This suggests that crop-to-weed gene flow may have created hybrid populations in some locations. Second, some populations were different from all the cultivated landraces with respect to both allozymes and quantitative traits. This probably results from variable gene Row in space and in time, due to demographic stochasticity in either natural or cultivated populations. Third. differentiation from cultivated landraces was only achieved for the quantitative traits but not for allozymes in two populations. This suggests that natural selection in some locations may oppose gene flow to establish cultivated traits into the natural introgressed populations.

Jenczewski, E., J. Ronfort, et al. (2003). "Crop-to-wild gene flow, introgression and possible fitness effects of transgenes." Environ Biosafety Res 2(1): 9-24.

Crop-to-wild gene flow has received close attention over the past ten years in connection with the development and cultivation of transgenic crops. In this paper, we review key examples of crop/wild sympatry and overlapping flowering phenology, pollen and seed dispersal, the barriers to hybridisation and introgression, the evolution and fate of interspecific hybrids, their fitness, and the potential cost of transgenes. We pay particular attention to ways in which the evolution and divergence between crops and their wild relatives may interfere with these successive steps. Our review suggests that crop-to-weed gene flow is highly idiosyncratic and that crop gene dispersion will certainly be very difficult to preclude totally. Future directions for research should thus focus on the long-term establishment and effects of transgenes on natural communities.

Johnson, B. and R. Dallimore (2002). "Beyond gene containment." Nat Biotechnol 20(9): 871-.

Johnson, K. L., A. F. Raybould, et al. (2007). "How does scientific risk assessment of GM crops fit within the wider risk analysis?" Trends Plant Sci 12(1): 1-5.

The debate concerning genetically modified crops illustrates confusion between the role of scientists and that of wider society in regulatory decision making. We identify two fundamental misunderstandings, which, if rectified, would allow progress with confidence. First, scientific risk assessment needs to test well-defined hypotheses, not simply collect data. Second, risk assessments need to be placed in the wider context of risk analysis to enable the wider 'non-scientific' questions to be considered in regulatory decision making. Such integration and understanding is urgently required because the challenges to regulation will escalate as scientific progress advances.

Johnson, P. G., S. R. Larson, et al. (2006). "Pollen-Mediated Gene Flow from Kentucky Bluegrass under Cultivated Field Conditions." Crop Sci 46(5): 1990-1997.

Kentucky bluegrass (Poa pratensis L.), one of the most commonly grown turfgrasses in temperate regions, is being developed for possible commercial release with transgenic traits. The use of this technology raises risk assessment questions because P. pratensis is perennial, often apomictic, competitive in many habitats, and hybridizes with other Poa. To further understand the potential environmental impact of a transgenic P. pratensis, we measured intra- and interspecific pollen-mediated gene flow in field conditions from P. pratensis to other Poa. We used a wagon-wheel design with a glyphosate (N-phosphono methyl-glycine) resistant P. pratensis as a pollen donor and a pollen receptor plot at 0 m and plots at 13 and 53 m along six equally spaced vectors. Each receptor plot included accessions from 25 Poa species. Seedlings from the receptor plants were screened for resistance to glyphosate and potential hybrids verified by PCR and genomic fingerprinting. Hybrids were found with P. arachnifera Torrey, P. interior Rydb., P. pratensis x P. secunda J. Presl, and three other P. pratensis entries, but did not occur with P. annua L., P. palustris L., P. trivialis L., or P. compressa L., among other species. Overall hybrid frequency was 0.048% and hybrid frequency at the 0-m distance was 0.53%. While apomixis in receptor plants and pollen competition likely reduced the number of hybrids, gene flow did occur but at low frequency and over short distances.

Jones, M. B., M. P. Schildhauer, et al. (2006). "The new bioinformatics: integrating ecological data from the gene to the biosphere." Annu Rev Ecol Evol Syst 37: 519-544.

Just, R. E., J. M. Alston, et al. (2006). Regulating Agricultural Biotechnology: Economics and Policy. New York, Springer.

This book presents the first thorough economic analysis of current agricultural biotechnology regulation. The contributors, most of whom are agricultural economists working either in universities or NGOs, address issues such as commercial pesticides, the costs of approving new products, liability, benefits, consumer acceptance, regulation and its impacts, transgenic crops, social welfare implications, and biosafety.

Kaiser, J. (2001). "Ecology. Words (and axes) fly over transgenic trees." Science 292(5514): 34-36.

Kapuscinski, A. R. (2005). "Current scientific understanding of the environmental biosafety of transgenic fish and shellfish." Rev Sci Tech 24(1): 309-322.

A fluorescent zebrafish was the first genetically engineered animal to be marketed, and biotechnologists are developing many transgenic fish and shellfish. Biosafety science is not sufficiently advanced to be able to draw scientifically reliable and broadly trusted conclusions about the environmental effects of these animals. The science is best developed for identifying hazards posed by environmental spread of a transgenic fish or shellfish and least developed for assessing potential ecological harms of spread. Environmental spread of certain transgenic fish or shellfish could be an indirect route of entry into the human food supply. The management of predicted environmental risks is in its infancy and has thus far focused on the first step of the risk management process, i.e. risk reduction, via a few confinement methods. There is a critical need to improve scientific methods of environmental safety assessment and management and to gather empirical data needed to substantiate biosafety conclusions and to effectively manage transgenic fish and shellfish. Scientists and potentially affected parties should participate in prioritising the knowledge gaps to be addressed.

Kapuscinski, A. R., K. R. Hayes, et al., Eds. (2007). Environmental Risk Assessment of Genetically Modified Organisms: Methodologies for Transgenic Fish. Wallingford, UK, CABI.

Kareiva, P. and M. Marvier (2007). "Conservation for the people." Sci Am 297(4): 50-57.

Kareiva, P., I. M. Parker, et al. (1996). "Can we use experiments and models in predicting the invasiveness of genetically engineered organisms?" Ecology 77(6): 1670-1675.

Kareiva, P., S. Watts, et al. (2007). "Domesticated nature: shaping landscapes and ecosystems for human welfare." Science 316(5833): 1866-1869.

Like all species, humans have exercised their impulse to perpetuate and propagate themselves. In doing so, we have domesticated landscapes and ecosystems in ways that enhance our food supplies, reduce exposure to predators and natural dangers, and promote commerce. On average, the net benefits to humankind of domesticated nature have been positive. We have, of course, made mistakes, causing unforeseen changes in ecosystem attributes, while leaving few, if any, truly wild places on Earth. Going into the future, scientists can help humanity to domesticate nature more wisely by quantifying the tradeoffs among ecosystem services, such as how increasing the provision of one service may decrease ecosystem resilience and the provision of other services.

Keegstra, K. (2005). Turning green into yellow: Improving plants for use as home-grown biofuels.

Kerlan, M. C., A. M. Chevre, et al. (1993). "Interspecific Hybrids between a Transgenic Rapeseed (Brassica- Napus) and Related Species - Cytogenetical Characterization and Detection of the Transgene." Genome 36(6): 1099-1106.

In interspecific hybrids produced between a transgenic rapeseed, an allotetraploid species, resistant to herbicide, phosphinotricin, and five diploid related species, the risk for gene introgression in weed genomes was explored through cytogenetic and bar gene characterizations. Among the 75 hybrids studied, most had the expected triploid structure, with the exception of B. napus - B. oleracea amphidiploid plants and one B. napus - S. arvensis amphidiploid plant. In triploid hybrid plants, the reciprocal hybrids did not exhibit any difference in their meiotic behavior. The comparison of the percentage of chromosome pairing in the hybrids with that of haploid rapeseed permit to conclude that allosyndesis between AC genomes and related species genomes took place. This possibility of recombination was confirmed by the presence of multivalent associations in all the interspecific hybrids. Nevertheless, in B. napus - B. adpressa hybrids a control of chromosome pairing seemed to exist. The possibility of amphidiploid plant production directly obtained in the F-1 generation increased the risk of gene dispersal. The B. napus B. oleracea amphidiploid plant presented a meiotic behavior more regular than that of the B. napus - S. arvensis amphidiploid plant. Concerning the herbicide bar gene characterization, the presence of the gene detected by DNA amplification was correlated with herbicide resistance, except for two plants. Different hypotheses were proposed to explain these results. A classification of the diploid species was established regarding their gene dispersal risk based on the rate of allosyndesis between chromosomes of AC genomes of rapeseed and the genomes of the related species.

Kirk, D. D., K. McIntosh, et al. (2005). "Risk analysis for plant-made vaccines." Transgenic Res 14(4): 449-462.

The production of vaccines in transgenic plants was first proposed in 1990 however no product has yet reached commercialization. There are several risks during the production and delivery stages of this technology, with potential impact on the environment and on human health. Risks to the environment include gene transfer and exposure to antigens or selectable marker proteins. Risks to human health include oral tolerance, allergenicity, inconsistent dosage, worker exposure and unintended exposure to antigens or selectable marker proteins in the food chain. These risks are controllable through appropriate regulatory measures at all stages of production and distribution of a potential plant-made vaccine. Successful use of this technology is highly dependant on stewardship and active risk management by the developers of this technology, and through quality standards for production, which will be set by regulatory agencies. Regulatory agencies can also negatively affect the future viability of this technology by requiring that all risks must be controlled, or by applying conventional regulations which are overly cumbersome for a plant production and oral delivery system. The value of new or replacement vaccines produced in plant cells and delivered orally must be considered alongside the probability and severity of potential risks in their production and use, and the cost of not deploying this technology--the risk of continuing with the status quo alternative.

Klein, E. K. and C. Laredo (1999). "Optimal sampling designs for studies of gene flow: A comment on Assuncao and Jacobi." Evolution 53(6): 2002-2005.

Klein, E. K., C. Lavigne, et al. (2003). "Corn pollen dispersal: Quasi-mechanistic models and field experiments." Ecological Monographs 73(1): 131-150.

To make quantitative predictions about the pollen dispersal of a plant species under different environmental conditions, it is necessary to determine its individual pollen dispersal function. i.e., the two-dimensional density function describing the probability that a pollen grain emitted in (0, 0) fertilizes an ovule in (x, NI). This function will depend on biological and climate parameters. We present models for the individual dispersal function of corn. These models are based on Brownian motion with drift and integrate biological (difference of height between male and female flowers) and aerodynamic (settling velocity, wind speed, air turbulence) parameters. The models presented differ in the importance of vegetation in stopping the paths of pollen grains.The models were fitted to data from two large field experiments of corn using the color of kernels as a phenotypic marker for pollen dispersal. The resulting estimations for the parameters of the models and comparisons between models indicate that (1) these models can provide good predictions of the observed data, (2) vegetation is not the major obstacle that stops pollen paths, and (3) there is a benefit in considering the difference in height between male and female flowers. Furthermore, values of the parameters estimated from dispersal data appear consistent with meteorological and biological data acquired independently.

Klinger, T., D. R. Elam, et al. (1991). "Radish as a Model System for the Study of Engineered Gene Escape Rates Via Crop-Weed Mating." Conservation Biology 5(4): 531-535.

Engineered genes in transgenic crops may escape into the ambient environment via crop-weed hybridization. However, natural crop-weed mating rates (gene flow) are largely unknown. We measured mating between wild and cultivated radishes in an experiment that simulated natural stands around seed multiplication plots. We used a genetic marker to identify crop-weed mating events. Although weeds at the cultivar plot margin (1 m distance) received much more gene flow than distant plants, detectable gene flow occurred at our most distant site (1000 m). For insect-pollinated, outcrossing crops like radish, strategies other than distance must be employed to ensure complete isolation.

Klinger, T. and N. C. Ellstrand (1994). "Engineered Genes in Wild Populations - Fitness of Weed-Crop Hybrids of Raphanus-Sativus." Ecological Applications 4(1): 117-120.

The transfer of engineered genes (transgenes) from crops to natural populations will depend first on mating between the crop and related weeds and then upon the relative fitness of the weed-crop hybrid. While weed-crop hybridization is known to occur readily under agricultural conditions, almost nothing is known of the fitness of the hybrids produced. Therefore, we measured the relative fitness of weedy radishes and their sibling weed-crop hybrids under field conditions. Specifically, we compared germination success, time to first flowering, fruit production, seed production, and frequency of transmission of the crop allele to seed progeny. Hybrids showed significantly greater fruit and seed production, and equaled weeds in all other measured characters. Thus, in this experiment, the fitness of hybrids exceeded that of their wild siblings. These results suggest that, in at least this system, neutral or advantageous transgenes introduced into natural populations will tend to persist.

Konig, A., A. Cockburn, et al. (2004). "Assessment of the safety of foods derived from genetically modified (GM) crops." Food Chem Toxicol 42(7): 1047-1088.

This paper provides guidance on how to assess the safety of foods derived from genetically modified crops (GM crops); it summarises conclusions and recommendations of Working Group 1 of the ENTRANSFOOD project. The paper provides an approach for adapting the test strategy to the characteristics of the modified crop and the introduced trait, and assessing potential unintended effects from the genetic modification. The proposed approach to safety assessment starts with the comparison of the new GM crop with a traditional counterpart that is generally accepted as safe based on a history of human food use (the concept of substantial equivalence). This case-focused approach ensures that foods derived from GM crops that have passed this extensive test-regime are as safe and nutritious as currently consumed plant-derived foods. The approach is suitable for current and future GM crops with more complex modifications. First, the paper reviews test methods developed for the risk assessment of chemicals, including food additives and pesticides, discussing which of these methods are suitable for the assessment of recombinant proteins and whole foods. Second, the paper presents a systematic approach to combine test methods for the safety assessment of foods derived from a specific GM crop. Third, the paper provides an overview on developments in this area that may prove of use in the safety assessment of GM crops, and recommendations for research priorities. It is concluded that the combination of existing test methods provides a sound test-regime to assess the safety of GM crops. Advances in our understanding of molecular biology, biochemistry, and nutrition may in future allow further improvement of test methods that will over time render the safety assessment of foods even more effective and informative.

Krayer von Krauss, M. P., E. A. Casman, et al. (2004). "Elicitation of expert judgments of uncertainty in the risk assessment of herbicide-tolerant oilseed crops." Risk Anal 24(6): 1515-1527.

One of the lay public's concerns about genetically modified (GM) organisms (GMO) and related emerging technologies is that not all the important risks are evaluated or even identified yet--and that ignorance of the unanticipated risks could lead to severe environmental or public health consequences. To some degree, even the scientists who participated in the analysis of the risks from GMOs (arguably the people most qualified to critique these analyses) share some of this concern. To formally explore the uncertainty in the risk assessment of a GM crop, we conducted detailed interviews of seven leading experts on GM oilseed crops to obtain qualitative and quantitative information on their understanding of the uncertainties associated with the risks to agriculture from GM oilseed crops (canola or rapeseed). The results of these elicitations revealed three issues of potential concern that are currently left outside the scope of risk assessments. These are (1) the potential loss of the agronomic and environmental benefits of glyphosate (a herbicide widely used in no-till agriculture) due to the combined problems of glyphosate-tolerant canola and wheat volunteer plants, (2) the growing problem of seed lot contamination, and (3) the potential market impacts. The elicitations also identified two areas where knowledge is insufficient. These are: the occurrence of hybridization between canola and wild relatives and the ability of the hybrids to perpetuate themselves in nature, and the fate of the herbicide-tolerance genes in soil and their interaction with soil microfauna and -flora. The methodological contribution of this work is a formal approach to analyzing the uncertainty surrounding complex problems.

Kuiper, H. A., A. Konig, et al. (2004). "Safety assessment, detection and traceability, and societal aspects of genetically modified foods. European Network on Safety Assessment of Genetically Modified Food Crops (ENTRANSFOOD). Concluding remarks." Food Chem Toxicol 42(7): 1195-1202.

The most important results from the EU-sponsored ENTRANSFOOD Thematic Network project are reviewed, including the design of a detailed step-wise procedure for the risk assessment of foods derived from genetically modified crops based on the latest scientific developments, evaluation of topical risk assessment issues, and the formulation of proposals for improved risk management and public involvement in the risk analysis process.

Kuparinen, A., F. Schurr, et al. (2007). "Air-mediated pollen flow from genetically modified to conventional crops." Ecological Applications 17(2): 431-440.

Tools for estimating pollen dispersal and the resulting gene flow are necessary to assess the risk of gene flow from genetically modified ( GM) to conventional fields, and to quantify the effectiveness of measures that may prevent such gene. ow. A mechanistic simulation model is presented and used to simulate pollen dispersal by wind in different agricultural scenarios over realistic pollination periods. The relative importance of landscape-related variables such as isolation distance, topography, spatial configuration of the. elds, GM field size and barrier, and environmental variation are examined in order to. nd ways to minimize gene. ow and to detect possible risk factors. The simulations demonstrated a large variation in pollen dispersal and in the predicted amount of contamination between different pollination periods. This was largely due to variation in vertical wind. As this variation in wind conditions is difficult to control through management measures, it should be carefully considered when estimating the risk of gene. ow from GM crops. On average, the predicted level of gene. ow decreased with increasing isolation distance and with increasing depth of the conventional. eld, and increased with increasing GM field size. Therefore, at a national scale and over the long term these landscape properties should be accounted for when setting regulations for controlling gene. ow. However, at the level of an individual. eld the level of gene flow may be dominated by uncontrollable variation. Due to the sensitivity of pollen dispersal to the wind, we conclude that gene. ow cannot be summarized only by the mean contamination; information about the frequency of extreme events should also be considered. The modeling approach described in this paper offers a way to predict and compare pollen dispersal and gene. ow in varying environmental conditions, and to assess the effectiveness of different management measures.

Kuvshinov, V., K. Koivu, et al. (2001). "Molecular control of transgene escape from genetically modified plants." Plant Science 160(3): 517-522.

Potential risks of gene escape from transgenic crops through pollen and seed dispersal are being actively discussed and have slowed down full utilization of gene technology in crop improvement. To ban the transgene flow, barren zones and 'terminator' technology were developed as GMO risk management technologies in transgenic crops. Unfortunately, the technologies have not protected reliably the transgene migration to wild relatives. The present study offers a novel molecular technique to eliminate gene flow from transgenic plants to wild relatives by recoverable block of function (RBF). The RBF consists of a blocking sequence linked to the gene of interest and a recovering sequence, all in one transformable construct. The blocking sequence blocks a certain molecular or physiological function of the host plant. Action of the blocking sequence leads to the death of the host plant or to an alteration in its phenotype resulting in inability for sexual reproduction in nature. The recovering construct recovers the blocked function of the host plant. The recovering construct is regulated externally by a specific chemical or physical treatment of the plants and does not act under natural conditions. In nature, hybrids of the transgenic plants with its wild relatives carrying the RBF will die or be unable to reproduce because of the blocking construct action. A wet-king model of RBF is described in this report as one example of the RBF concept. This RBF example is based on ba, nase (the blocking construct) and barstar (the recovering construct) gene expression in tobacco under sulfhydryl endopeptidase (SH-EP) and a heat shock (HS) promoter, respectively. (C) 2001 Elsevier Science ireland Ltd. All rights reserved.

Lackey, R. T. (2007). "Science, scientists, and policy advocacy." Conserv Biol 21(1): 12-17.

I am concerned that we scientists in conservation biology, ecology, natural resources, environmental science, and similar disciplines are collectively slipping into a morass that risks marginalizing the contribution of science to public policy. Advocating personal positions on ecological policy issues has become widely tolerated as acceptable professional behavior and is even encouraged by a substantial fraction of the scientific community (Marris 2006; Scott et al. 2007). Scientists are uniquely qualified to participate in public policy deliberations and they should, but advocating for their policy preferences is not appropriate.

Lang, A., E. Lauber, et al. (2007). "Early-tier tests insufficient for GMO risk assessment." Nat Biotechnol 25(1): 35-36; author reply 36-37.

Lassen, J. and A. Jamison (2006). "Genetic technologies meet the public: the discourses of concern." Sci Technol Human Values 31(1): 8-28.

To clarify concerns that the public has with genetic technologies, the article presents the results of focus group interviews conducted in Denmark in 2000. The concerns of the public are divided into three ideal-typical categories: social (dealing with environmental and health risks), economic (dealing with both the threats and opportunities of the new technologies), and cultural (taking up ethical and moral concerns). Following a general discussion of why it is important to take these discourses of concern seriously, each discursive category is discussed with examples taken from the focus group interviews.

Lavigne, C., E. K. Klein, et al. (2002). "Using seed purity data to estimate an average pollen mediated gene flow from crops to wild relatives." Theoretical and Applied Genetics 104(1): 139-145.

Gene flow from crops to wild related species has been recently under focus in risk-assessment studies of the ecological consequences of growing transgenic crops. However, experimental studies addressing this question are usually temporally or spatially limited. Indirect population-structure approaches can provide more global estimates of gene flow, but their assumptions appear inappropriate in an agricultural context. In an attempt to help the committees providing advice on the release of transgenic crops, we present a new method to estimate the quantity of genes migrating from crops to populations of related wild plants by way of pollen dispersal. This method provides an average estimate at a landscape level. Its originality is based on the measure, of the inverse gene flow, i.e. gene flow from the wild plants to the crop. Such gene flow results in an observed level of impurities from wild plants in crop seeds. This level of impurity is usually known by the seed producers and, in any case, its measure is easier than a direct screen of wild populations because crop seeds are abundant and their genetic profile is known. By assuming that wild and cultivated plants have a similar individual pollen dispersal function, we infer the level of pollen-mediated gene flow from a crop to the surrounding wild populations from this observed level of impurity. We present an example for sugar beet data. Results suggest that under conditions of seed production in France (isolation distance of 1,000 in) wild beets produce high numbers of seeds fathered by cultivated plants.

Lavigne, C., E. K. Klein, et al. (1998). "A pollen-dispersal experiment with transgenic oilseed rape. Estimation of the average pollen dispersal of an individual plant within a field." Theoretical and Applied Genetics 96(6-7): 886-896.

In order to help establish a basis for the assessment of gene flow associated with the large-scale release of transgenic oilseed rape, we previously designed a method which makes it possible to retrieve the average pollen dispersal of a single plant from that of a large source plot. The 'individual' pollen distribution thus obtained is less dependent on the experimental design than pollen distributions usually published and could therefore be used to model the possible escape of a transgene from commercial transgenic crops. In this study we report on a field experiment set up to study the pollen dispersal from an herbicide-resistant transgenic variety of oilseed rape and to test the applicability of the method on the experimental data. Two techniques were used to determine the individual pollen dispersal, and their outcomes are compared. The results suggest that approximately half of the pollen produced by an individual plant fell within 3m and that the probability of fertilisation afterwards decreased slowly along a negative exponential of the distance. Comparison with the global pollen distribution from the source plot indicates that pollen-dispersal distributions based on dispersal from whole plots instead of individual plants would have underestimated the proportion of pollen that was dispersed over average or long distances.

Lee, D. and E. Natesan (2006). "Evaluating genetic containment strategies for transgenic plants." Trends Biotechnol 24(3): 109-114.

One of the primary concerns about genetically engineered crop plants is that they will hybridize with wild relatives, permitting the transgene to escape into the environment. The likelihood that a transgene will spread in the environment depends on its potential fitness impact. The fitness conferred by various transgenes to crop and/or wild-type hybrids has been evaluated in several species. Different strategies have been developed for reducing the probability and impact of gene flow, including physical separation from wild relatives and genetic engineering. Mathematical models and empirical experimental evidence suggest that genetic approaches have the potential to effectively prevent transgenes from incorporating into wild relatives and becoming established in wild populations that are not reproductively isolated from genetically engineered crops.

Lefol, E., A. Fleury, et al. (1996). "Gene dispersal from transgenic crops .2. Hybridization between oilseed rape and the wild heavy mustard." Sexual Plant Reproduction 9(4): 189-196.

The risk of release of genetically modified oilseed rape (Brassica napus) was investigated in relation to interspecific gene flow with hoary mustard (Hirschfeldia incana). Microscopic studies showed polymorphism within the population of hoary mustard for pollen germination on oilseed rape flowers. The transgenic herbicide-resistant and a commercial cultivar of oilseed rape were not different for pollen behaviour and ovule fertilization. Pollen tube growth was slow and erratic in interspecific crosses. Fertilization efficiency of oilseed rape and hoary mustard pollen in interspecific crosses was 15% and 1.3%, respectively, of that in intraspecific crosses. This unequal efficiency in reciprocal crosses was confirmed by hybrid seed set in pods. There was no post-zygotic barrier to the development of hybrid embryos in hoary mustard pods. Up to 26 spontaneous hybrids per male sterile oilseed rape plant, and one per hoary mustard plant, were obtained in field experiments. Hybrids were identified by isozyme electrophoresis, morphology and cytology. All hybrids were triploid with 26 chromosomes, and had low fertility. They produced 0.5 seeds per plant after spontaneous backcrossing with hoary mustard. Some of these descendants were produced from unreduced gametes. Our results suggest that gene flow is likely to occur, but its actual frequency under crop growing conditions remains to be estimated.

Legere, A. (2005). "Risks and consequences of gene flow from herbicide-resistant crops: canola (Brassica napus L) as a case study." Pest Manag Sci JT - Pest management science. 61(3): 292-300.

Data from the literature and recent experiments with herbicide-resistant (HR) canola (Brassica napus L) repeatedly confirm that genes and transgenes will flow and hybrids will form if certain conditions are met. These include sympatry with a compatible relative (weedy, wild or crop), synchrony of flowering, successful fertilization and viable offspring. The chance of these events occurring is real; however, it is generally low and varies with species and circumstances. Plants of the same species (non-transgenic or with a different HR transgene) in neighbouring fields may inherit the new HR gene, potentially generating plants with single and multiple HR. For canola, seed losses at harvest and secondary dormancy ensures the persistence over time of the HR trait(s) in the seed bank, and the potential presence of crop volunteers in subsequent crops. Although canola has many wild/weedy relatives, the risk of gene flow is quite low for most of these species, except with Brassica rapa L. Introgression of genes and transgenes in B rapa populations occurs with apparently little or no fitness costs. Consequences of HR canola gene flow for the agro-ecosystem include contamination of seed lots, potentially more complex and costly control strategy, and limitations in cropping system design. Consequences for non-agricultural habitats may be minor but appear largely undocumented.

Letourneau, D. K., G. S. Robinson, et al. (2003). "Bt crops: predicting effects of escaped transgenes on the fitness of wild plants and their herbivores." Environ Biosafety Res 2(4): 219-246.

One prominent concern about genetically modified crops is the possibility of environmental impacts from the movement of fitness-enhancing traits to wild plant populations. Decisions to deregulate Bt crops in the USA have relied strongly on arguments that these crops will not interbreed with wild relatives in the permitted growing regions. Limited attention therefore has been directed to analyses of the consequences of gene flow. To provide a transparent evaluation process for risks associated with insecticidal transgene escape, we crafted a series of questions designed to guide this aspect of the risk assessment. We then explored the current knowledge base available for answering such risk-related questions for three Bt crops (cotton, rapeseed, and rice). First, we generated a list of wild relatives of these crops. A definitive list of potential transgene recipients is not yet possible for some crops. Sufficient data are not available for some crops to eliminate certain related plant species from consideration of fertile hybrid formation, thus making lists for these crops subject to speculation. Second, we queried the HOSTS database (UK) to obtain a worldwide listing of lepidopteran species that feed on these crops and their wild relatives, and to determine the host range of the larvae. To our knowledge, this list of 502 lepidopteran species is the first such list published for these crops and wild crop relatives. Third, we used a data set maintained by the Canadian Forest Service to assess Bt toxin susceptibility for these lepidopterans. Only 3% of those species have been tested for susceptibility; and the literature suggests that generalizations about susceptibility among taxa are difficult due to the variability within families. Fourth, we consulted the literature to interpret what is known about the ability of lepidopterans to regulate plant fitness or invasiveness. We could not eliminate the possibility of ecological release due to plant resistance against lepidopterans. In fact, there is strong experimental evidence that lepidopteran herbivores do limit the distribution and/or abundances of at least some wild plant species. Neither could we eliminate the possibility that non-target lepidopterans might have important functions in the ecosystem as pollinators or alternate hosts to natural enemies of pest species. This study suggests that crucial data are lacking for the development of a credible scientific basis to confirm or deny environmental risks associated with the escape of Bt transgene constructs to wild relatives. Given the absence of information on the identity, level of susceptibility, and ecological roles of lepidopterans exploiting specific wild relatives of Bt crops, we suggest that new efforts be directed to assessing possible consequences of lepidopteran mortality on resistant wild relatives.

Libiakova, G., B. Jorgensen, et al. (2001). "Efficacy of an intron-containing kanamycin resistance gene as a selectable marker in plant transformation." Plant Cell Reports 20(7): 610-615.

In this project we have analysed the use of an intron- containing neomycin phosphotransferase II nptII - gene. The advantage of this construct is that only eukaryotic organisms will be able to process this gene. Accordingly, the theoretical risk of horizontal gene flow of antibiotic resistance genes from transgenic plants to enteric bacteria is eliminated. The ST-LS1 intron IV2 from potato was inserted into the coding region of nptII Transformation of Solanum tuberosum (potato) and Nicotiana tabacum (tobacco) with constructs containing the intron nptII showed similar transformation frequencies to transformation with constructs containing the normal nptII. Analysis of total DNA and RNA confirmed that the intron- containing nptII gene was present in the plants and that the mRNA was processed correctly.

Lichtenberg, E. (2006). Regulation of technology in the context of risk generation. Regulating Agricultural Biotechnology: Economics and Policy. R. E. Just and E. al, Springer: 283-299.

This chapter uses a generic model of the risk-generating process and an approach to accommodating uncertainty about risk to draw some inferences about regulating transgenic crops. The analysis suggests that regulation should concentrate on reducing uncertainty about environmental impacts of transgenic crops. Thus, it may be cost effective for the United States to de-emphasize restrictions on planting but expand post-commercialization monitoring. The analysis also indicates that there are tractable ways of incorporating firms’ and consumers’ reactions to regulation into models of the risk-generation process. The main impediment to doing so is a lack of empirical models, which suggests a need for empirical work aimed at producing results that can be extrapolated to biotechnology regulation. The model can be extended easily to accommodate multiple, heterogeneous sites.

Lilley, A. K., M. J. Bailey, et al. (2006). "Life in earth: the impact of GM plants on soil ecology?" Trends Biotechnol 24(1): 9-14.

The impact of changes incurred by agricultural biotechnology has led to concern regarding soil ecosystems and, rightly or wrongly, this has focused on the introduction of genetically modified (GM) crops. Soils are key resources, with essential roles in supporting ecosystems and maintaining environmental quality and productivity. The complexity of soils presents difficulties to their inclusion in the risk assessment process conducted for all GM plants. However, a combined approach, informed by both soil ecology and soil quality perspectives, that considers the impacts of GM crops in the context of conventional agricultural practices can provide a regulatory framework to ensure the protection of soils without being overly restrictive.

Linder, C. R. (1998). "Potential persistence of transgenes: Seed performance of transgenic canola and wild x canola hybrids." Ecological Applications 8(4): 1180-1195.

Because wild, weedy-ephemeral species take advantage of periodic disturbance For growth and reproduction, many have considerable seed dormancy and longevity, coupled with germination cued on environmental changes correlated with disturbance. Brassica napus canola is derived from a weedy ephemeral and has sexually compatible wild relatives that are weedy ephemerals, most notably B. rapa. Hence, if transgenes introduced into B. napus canola alter its seed bank dynamics to be more similar to its wild relatives, the chance of transgene escape and persistence is increased. Further, if introgression of the transgene into a wild relative enhances or does not disrupt the seed bank dynamics of wild plants, the transgene could persist in wild populations. I conducted experiments with transgenic, oil-modified B. napus canola (high-stearate and high-laurate types) and wild B. rapa x B. napus canola hybrids (high-laurate type) to determine whether they possessed seed dormancy and germination cuing characteristics favoring persistence of escaped transgenes. Seeds of high-stearate B. napus canola and its untransformed parental type were germinated in growth chambers in a complete factorial design of light (full light, darkness, simulated foliage shade), nutrient concentration (high, low), and temperature (10 degrees, 20 degrees, 35 degrees C). Most combinations of factors did not alter high-stearate canola's timing of germination or total proportion of seeds germinated relative to its nonpersistent parental control. Where effects were seen, they were disadvantageous, with high-stearate seeds germinating more slowly than controls (35 degrees C:full light:high nutrient) and in lower proportions (35 degrees C:darkness:high nutrient and 35 degrees C:full Light:high nutrient). Ungerminated high- stearate seeds in treatment combinations having reduced germination were primarily dormant rather than dead. Although most of their dormancy was enforced by high temperature, under some conditions (35 degrees C:full light:high nutrients and 35 degrees C:darkness:low nutrients), I detected significantly higher levels of induced dormancy for high-stearate seeds relative to controls. Hence, persistent high-stearate canola seed banks could form under some field conditions. For high- laurate B. napus canola and high-laurate wild B. rapa x B. napus canola hybrids and their controls, I germinated seeds in growth chambers, varying light and nutrients using the same treatments as above in a complete factorial design. Temperature was maintained at 10 degrees C. High-laurate canola germinated later than its parental control, with the difference enhanced by low nutrients, In low nutrients, high-laurate canola also germinated at a lower proportion than its control. Both of these altered germination characteristics do not favor population persistence of high-laurate canola. Under some conditions (darkness:high nutrients), high-laurate canola had higher overall dormancy and induced dormancy than its control, suggesting the possibility of increased seed bank persistence. Finally, in spite of expectations that, the high-laurate wild x crop hybrid would show strong maternal effects, this hybrid and the hybrid control always germinated at proportions at or near 1.0, whereas the wild parent had very low germination proportions and high levels of dormancy, especially in simulated foliage shade. These results suggest that high- laurate wild-crop hybrids lack germination cuing mechanisms and will germinate primarily at inappropriate times. However, when they do germinate with wild B. rapa, they are likely to compete well with it: because the high-laurate hybrids germinated and grew as fast or faster than their wild parental control. This should provide opportunities for backcrossing to wild B. rapa.

Linder, C. R. and J. Schmitt (1994). "Assessing the Risks of Transgene Escape through Time and Crop- Wild Hybrid Persistence." Molecular Ecology 3(1): 23-30.

Transgenes introduced into crops can escape in time, as well as space, via the seed bank. For annual plants, especially ruderals, seed bank behaviour may be the most important factor determining population persistence. Crop seeds may exhibit some dormancy and germination cueing in the soil but are expected to be less able to persist than their wild relatives, which often have considerable dormancy and longevity, as well as effective germination cueing responses. Crop-wild hybrids may have seed bank characteristics more suited to persistence, and maternal effects may favour persistence of hybrids having wild plants for their female parent. Escape of transgenes via crop-wild hybrids presents unique concerns not present for crops. Hybrids can undergo natural selection and may back-cross with wild plants. We suggest methods that can be used in conjunction with evaluation of the relative fitness of crop-wild hybrids that will determine the likelihood of back-crossing. Accurate assessment of escape in time and transgene persistence via crop-wild hybrids requires proper plant materials. We emphasize the use of null segregants as controls for transgenic crops and for generating crop-wild hybrid controls for transgenic hybrids. Since good empirical and theoretical understanding of how individual genes influence the fate of plants in different environments is lacking, evaluation of escape in time and the persistence of transgenes via crop-wild hybrids should be on a case-by-case basis.

Linder, C. R., I. Taha, et al. (1998). "Long-term introgression of crop genes into wild sunflower populations." Theoretical and Applied Genetics 96(3-4): 339-347.

Hybrids between cultivated and wild sunflowers (Helianthus annuus) are frequently reported. As much as 42% of progeny from wild plants near cultivar fields are hybrids, and cultivar genes have been shown to persist in wild populations at least five generations. We report the effects of up to 40 years of persistent cultivar gene flow on the genetic structure of three wild H. annuus populations that are adjacent to cultivated fields, Eighteen cultivar-specific markers were surveyed in a total of 115 individuals. We also developed cultivar-based genetic maps for the markers and used them to see if marker patterns in the wild populations were consistent with introgression and if selection was acting jointly on unlinked loci. High levels of crop specific markers were detected in all three wild populations: ranging from 0.315 to 0.382, on average. All 115 plants had at least 1 cultivar marker. Introgression is the most likely explanation for the presence of crop-specific markers in the sympatric populations because (1) the markers were either not present or found at much lower levels in four allopatric populations, (2) markers that were genetically linked in the cultivar invariably showed linkage disequilibrium patterns in the sympatric populations consistent with introgression, and (3) homology tests ruled out convergent evolution as an alternate explanation. Hence, introgression of cultivar loci was widespread, and the sympatric wild populations have been replaced by advanced generation hybrids, Unlinked, introgressed markers did not show significant linkage disequilibria, indicating a lack of epistatic associations among introgressed markers. Hence, transgenes in cultivated sunflowers should readily introgress into sympatric wild populations, and their fate will be determined primarily by their fitness effects on the wild plants.

Lofstedt, R. E., B. Fischhoff, et al. (2002). "Precautionary principles: General definitions and specific applications to genetically modified organisms." Journal of Policy Analysis and Management 21(3): 381-407.

Precautionary principles have been proposed as a fundamental element of sound risk management. Their advocates see them as guiding action in the face of uncertainty, encouraging the adoption of measures that reduce serious risks to health, safety, and the environment. Their opponents may reject the very idea of precautionary principles, find specific principles unacceptably vague or see them as clearly doing economic damage-either to society as a whole or to their own interests. This article traces the development of alternative precautionary principles, primarily in Europe. Their adequacy is considered in one context where such principles have often been invoked, using genetically modified organisms (GMOs) in agriculture. Although some precautionary principles can be given analytical rigor, the concerns that they express strain the intellectual and institutional structure of conventional policy analysis. (C) 2002 by the Association for Policy Analysis and Management.

Losey, J. E., R. A. Hufbauer, et al. (2003). "Enumerating lepidopteran species associated with maize as a first step in risk assessment in the USA." Environ Biosafety Res 2(4): 247-261.

Pest management can have substantial impacts on non-target species both within and outside the units being managed. Assessment of these impacts is hampered by the lack of even the most basic checklist of the species present in most systems. The maize agroecosytem is of particular interest because of the large area covered and the intensity of widely varying forms of pest management. In this study a database of lepidopteran species that occur within the maize agroecosystem in the United States was compiled. The process was initiated by developing a list of plants present in maize using published sources and the first-hand knowledge of "weed" experts. This list of plant species associated with maize was then cross-listed with lepidopteran host feeding records using published sources. Finally, phenological profiles and conservation rankings were added. Although our list is not exhaustive, we found 132 plant species in 33 families associated with maize, and 229 lepidopteran species in 21 families that feed on these plants. The database of plants and lepidopteran species can be a starting point for assessment of risk to non-target Lepidoptera in maize from chemical control, biological control, and the use of transgenic Bt maize. The lepidopteran species associated with maize were found to be significantly less imperiled, as measured by their conservation rankings, than lepidopteran species as a whole in all habitats. This finding suggests that rare or endangered lepidopteran species are unlikely to be impacted by pest management in maize. Based on the likely lack of impact of pest management in maize on individual species, future studies should focus on potential impacts on the ecological services that lepidopteran species provide.

Losey, J. E., L. S. Rayor, et al. (1999). "Transgenic pollen harms monarch larvae." Nature 399(6733): 214.

Lu, B. R. and A. A. Snow (2005). "Gene flow from genetically modified rice and its environmental consequences." Bioscience 55(8): 669-678.

Within the next Jew years, many types of transgenic rice (Oryza sativa) will be ready for commercialization, including varieties with higher yields, greater tolerance of biotic and abiotic stresses, resistance to herbicides, improved nutritional quality, and novel pharmaceutical proteins. Although rice is primarily self-pollinating, its transgenes are expected to disperse to nearby weedy and wild relatives through pollen-mediated gene flow. Sexually compatible Oryza species often co-occur with the crop, especially in tropical countries, but little is known about how quickly fitness-enhancing transgenes will accumulate in these populations and whether this process will have any unwanted environmental consequences. For example, weedy rice could become much more difficult to manage if it acquires herbicide resistance, produces more seeds, or occurs in a wider range of habitats because of the spread of certain transgenes. Rice-growing countries urgently need publicly available ecological assessments of the risks and benefits of transgenic rice before new varieties are released.

Lu, B. R., Z. P. Song, et al. (2003). "Can transgenic rice cause ecological risks through transgene escape?" Progress in Natural Science 13(1): 17-24.

Alien transgene escape from genetically engineered rice to non-transgenic varieties or close wild relatives ( including weedy rice) may lead to unpredictable ecological risks. However, for transgene escape to occur three conditions need to be met: (i) spatially, transgenic rice and its non-transgenic counterparts or wild relatives should have sympatric distributions; (ii) temporally, the flowering time of transgenic rice and the non-transgenic varieties or wild relatives should overlap; and (iii) biologically, transgenic rice and its wild relative species should have such a sufficiently close relationship that their interspecific hybrids can have normal generative reproduction. This paper presents research data on the geographic distribution, flowering habits, interspecific hybridization, and gene flow of cultivated rice ( Oryza sativa) and its closely related wild relatives containing the AA genome. The objective is to estimate the possibility of transgene escape to non-transgenic rice varieties and wild relatives of rice, which may result in unpredictable ecological risks.

Luby, J. J. and R. J. McNicol (1995). "Gene Flow from Cultivated to Wild Raspberries in Scotland - Developing a Basis for Risk Assessment for Testing and Deployment of Transgenic Cultivars." Theoretical and Applied Genetics 90(7-8): 1133-1137.

In order to help establish a basis for assessing the risk associated with the testing and large-scale deployment of transgenic raspberries, wild and feral raspberry populations in Scotland were surveyed for evidence of the escape of genes introduced into raspberry cultivars by traditional breeding. The genes concerned were introduced into cultivars using traditional breeding techniques and were deployed at known times 20 to 30 years prior to the present survey. Escape of the semidominant L(1) gene, affecting fruit size and plant morphology, could not be detected after 30 years in test plots at the Scottish Crop Research Institute near Dundee. The recessive gene s, conferring spinelessness, was detected at very low frequencies (estimated at 0.004) in wild populations within the commercial production locales where cultivars carrying this gene had been introduced on a large scale beginning 21-years prior to this survey. This gene was not, however, found in any areas remote from the commercial production locales. The results of the survey indicate that escape does occur following large-scale deployment but that gene flow events are probably infrequent and spread is localized for genes having probable neutral selective value.

Madsen, K. H. and P. Sandoe (2005). "Ethical reflections on herbicide-resistant crops." Pest Manag Sci JT - Pest management science. 61(3): 318-325.

The introduction of genetically modified (GM) crops has caused a fierce public debate in Europe. Much of the controversy centres on possible risks to the environment. A specific problem here is that risk perception of the scientific experts differs from that of the public. In this paper, risks associated with herbicide-resistant crops are presented from the point of view of experts and lay people. In the public perception, herbicide-resistant (HR) crops are troublesome because of their association with two technologies: genetic engineering of crops and the use of herbicides. These technologies are perceived as risky because they seem to share certain features: in particular, their long-term effects are unknown and they are dreaded. Other value questions also come into play. The public seems to be concerned that risks are not outweighed by usefulness, that using HR crops is the wrong path to sustainable agriculture, that the individual's right to choose GM-free products may be violated, and that these crops are unnatural. In contrast, on the issue of the uncertainty inherent in risk assessment, experts and the public seem to share a good deal of ground.

Mamy, L. and E. Barriuso (2005). "Glyphosate adsorption in soils compared to herbicides replaced with the introduction of glyphosate resistant crops." Chemosphere JT - Chemosphere. 61(6): 844-855.

Use of glyphosate resistant crops was helpful in addressing observed increases in environmental contamination by herbicides. Glyphosate is a broad-spectrum herbicide, and its behaviour-as well as that of other herbicides-in soils is an important consideration for the overall environmental evaluation of genetically resistant crop introduction. However, few data have been published comparing glyphosate behaviour in soil to that of the herbicides that would be replaced by introduction of glyphosate resistant crops. This work compares glyphosate adsorption in soil with that of other herbicides frequently used in rape (trifluralin and metazachlor), sugarbeet (metamitron) and corn (sulcotrione). Herbicide adsorption was characterised in surface soils and in the complete soils profiles through kinetics and isotherms using batch equilibration methods. Pedological and molecular structure factors controlling the adsorption of all five herbicides were investigated. Glyphosate was the most strongly adsorbed herbicide, thus having the weakest potential for mobility in soils. Glyphosate adsorption was dependent on its ionisable structure in relation to soil pH, and on soil copper, amorphous iron and phosphate content. Trifluralin adsorption was almost equivalent to glyphosate adsorption, whereas metazachlor, metamitron and sulcotrione adsorption were lower. Trifluralin, metazachlor and metamitron adsorption increased with soil organic carbon content. Sulcotrione was the least adsorbed herbicide in alkaline soils, but its adsorption increased when pH decreased. Ranking the adsorption properties among the five herbicides, glyphosate and trifluralin have the lowest availability and mobility in soils, but the former has the broadest spectrum for weed control.

Manasse, R. S. (1992). "Ecological Risks of Transgenic Plants - Effects of Spatial- Dispersion on Gene Flow." Ecological Applications 2(4): 431-438.

The spread of advantageous transgenic genes from crop plants into wild and weedy relatives is a potential ecological problem. The available theory indicates that the spread of a gene, over space and time, will depend in part on the relative selective advantage of that gene, and in part on gene flow, or the probability distribution of gene movement from source to target plants within a single generation. Risk assessment will require knowledge of both. This paper describes an empirical investigation of the effect of spatial dispersion on gene flow in Brassica campestris, utilizing a system of wild genotypes for target plants, and agronomic genotypes with a marker gene for source plants. I have found that gene flow can be reliably modeled with an exponential probability density function, and that the mean of that distribution can vary with the spatial dispersion of plants. Two-dimensional arrays of plants had lower mean gene dispersal distance than did one-dimensional arrays. In contrast, the degree of clumping and the size of patches of plants in my experiments had no effect on gene flow. However, I found an increase in mean gene dispersal distance with increased distance between clumps of plants, or between individual plants in one year. These results imply that large isolation distances accompanied by a rare long-distance pollination event will ultimately increase the risk of gene spread.

Mandal, G. N. (2004). "Gaps, inexperience, inconsistencies, and overlaps: crisis in the regulation of genetically modified plants and animals." William Mary Law Rev 45(5): 2167-2259.

The regulation of genetically modified products pursuant to statutes enacted decades prior to the advent of biotechnology has created a regulatory system that is passive rather than proactive about risks, has difficulty adapting to biotechnology advances, and is highly fractured and inefficient--transgenic plants and animals are governed by at least twelve different statutes and five different agencies or services. The deficiencies resulting from this piecemeal approach to regulation unnecessarily expose society and the environment to adverse risks of biotechnology and introduce numerous inefficiencies into the regulatory system. These risks and inefficiencies include gaps in regulation, duplicative and inconsistent regulation, unnecessary increases in the cost of and delay in the development and commercialization of new biotechnology products. These deficiencies also increase the risk of further unnecessary biotechnology scares, which may cause public overreaction against biotechnology products, preventing the maximization of social welfare. With science and society poised to soar from first-generation biotechnology (focused on crops modified for agricultural benefit), to next-generation developments (including transgenic fish, insects, and livestock, and pharmaceutical-producing and industrial compound-producing plants and animals), it is necessary to establish a comprehensive, efficient, and scientifically rigorous regulatory system. This Article details how to achieve such a result through fixing the deficiencies in, and risks created by, the current regulatory structure. Ignoring many details, the solutions can be summarized in two categories. First, statutory and regulatory gaps that are identified must be closed with new legislation and regulation. Second, regulation of genetically modified products must be shifted from a haphazard model based on statutes not intended to cover biotechnology to a system based upon agency expertise in handling particular types of risks.

Martinez-Castillo, J., D. Zizumbo-Villarreal, et al. (2007). "Gene Flow and Genetic Structure in the Wild-Weedy-Domesticated Complex of Phaseolus lunatus L. in its Mesoamerican Center of Domestication and Diversity." Crop Sci 47(1): 58-66.

The role of gene flow in autogamous domesticated species diversity and their wild relatives is an issue that requires more field data. Using nine microsatellite loci, an analysis was done of the magnitude and direction of gene flow in the wild-weedy-domesticated complex of Phaseolus lunatus L. under traditional agricultural conditions in four regions on the Yucatan Peninsula, Mexico, its center of domestication and diversity in Mesoamerica. Two complementary methods were used. The Bayesian genotype assignment approach showed that recent gene flow was low at both the intraregional and interregional levels. The same was found with the frequency method for long-term gene flow (Nm intraregional from 0.31 to 0.51, and Nm interregional = 0.44). In addition, the gene flow from domesticate to wild populations was three times higher than in the opposite direction. This asymmetry can be explained by regional agricultural practices and seed selection criteria. Domesticate alleles were shown to be entering wild populations of different agricultural regions, suggesting exchange of domesticated seed between farmers of different regions. These results are very important because they show that P. lunatus on the Yucatan Peninsula has a predominantly domesticate to wild gene flow. This situation may lead to genetic assimilation of wild lima bean by its domesticated counterpart and may lead to the possible escape of transgenes in this center of origin and diversity.

Martinez-Ghersa, M. A., C. A. Worster, et al. (2003). "Concerns a weed scientist might have about herbicide-tolerant crops: A revisitation." Weed Technology 17(1): 202-210.

Over a decade ago, the Weed Science Society of America sponsored a symposium on the then emerging technology of herbicide-tolerant crops (HTCs). The symposium and subsequent proceedings addressed potential benefits and concerns about that new technology to control weeds. Technological, biological, and ethical questions were addressed that were likely to emerge from the widespread adoption of HTCs. It was suggested at that time that if such questions were answered, HTC development would proceed on a more solid foundation, whereas continued uncertainty and criticism would probably result if the questions were not answered. We now review developments in HTC technology. Questions and concerns posed one decade ago are still pertinent, but current knowledge is still insufficient to address them. Adoption of HTC has risen dramatically since their commercial introduction, but there is still no evidence of associated production cost reductions or enhanced yields.

Marvier, M. (2001). "Ecology of transgenic crops." American Scientist 89(2): 160-117.

Concerns about risks posed by transgenic agricultural crops generally focus on direct risks to human health. There is, however, a set of potential ecological risks that bears equal scrutiny. Transgenic crops designed to resist or kill herbivores, for example, may spread their genes to non-crop species, producing virulent weed species. Likewise, these crops may negatively affect populations of beneficial insects, as was the case in the recent controversial finding that transgenic corn may increase mortality in monarch butterfly caterpillars. Assessing such risks is inherently difficult, but the impact of ignoring them could be devastating.

Marvier, M. (2002). "Improving risk assessment for nontarget safety of transgenic crops." Ecological Applications 12(4): 1119-1124.

In many countries, government regulations require environmental risk assessment prior to commercial sale and widespread planting of transgenic crops. Here I evaluate the design and statistical rigor of experiments used by industry to assess the safety of transgenic plants for nontarget organisms, as required under U.S. regulations. This review reveals that a few simple improvements in experimental design could greatly increase the rigor and information content of studies required under current regulations. For example, although most experiments were conducted for 1-4 wk, some of the tested species can live a year or more and could experience much longer periods of exposure. Moreover. the number of replicates used in these studies was generally quite small (usually 2-6 replicates per treatment), resulting in experiments that had little chance of detecting real effects. Clearly, sample sizes should be bolstered, and nonsignificant results should be accompanied by an analysis of statistical power. In addition, information readily available over the Internet is insufficient for a quantitative assessment of a transgenic crop's safety. Improved access to information regarding the details of risk assessment studies could greatly increase the public's ability to evaluate industry's claims of safety.

Marvier, M., C. McCreedy, et al. (2007). "A meta-analysis of effects of Bt cotton and maize on nontarget invertebrates." Science 316(5830): 1475-1477.

Although scores of experiments have examined the ecological consequences of transgenic Bacillus thuringiensis (Bt) crops, debates continue regarding the nontarget impacts of this technology. Quantitative reviews of existing studies are crucial for better gauging risks and improving future risk assessments. To encourage evidence-based risk analyses, we constructed a searchable database for nontarget effects of Bt crops. A meta-analysis of 42 field experiments indicates that nontarget invertebrates are generally more abundant in Bt cotton and Bt maize fields than in nontransgenic fields managed with insecticides. However, in comparison with insecticide-free control fields, certain nontarget taxa are less abundant in Bt fields.

Maskell, L. C., A. F. Raybould, et al. (1999). "Effects of turnip mosaic virus and turnip yellow mosaic virus on the survival, growth and reproduction of wild cabbage (Brassica oleracea)." Annals of Applied Biology 135(1): 401-407.

Wild plants of Brassica oleracea (wild cabbage) are commonly infected with turnip mosaic potyvirus (TuMV), turnip yellow mosaic tymovirus (TYMV) and several other viruses. A field experiment in which plants were inoculated either with TuMV or TYMV showed that virus infection significantly reduced survival, growth and reproduction. Relative to water inoculated-controls, plants infected with TYMV had greater mortality, were shorter, had a smaller leaf area and number, showed a greater amount of damage from herbivory and chlorosis, were less likely to flower and produced fewer pods and lower total seed output. Plants infected with TuMV did not appear to be adversely affected at first; however, mortality after 18 months was higher than control plants. Although TuMV infection had no effect on the number of plants flowering, the infected plants did produce fewer pods and a lower total seed output. We conclude that both viruses can significantly affect vegetative and reproductive performance of wild cabbage and hence that introgression of virus resistance (particularly when conferred by a major gene or a transgene) from a crop might increase plant fitness in natural populations of this species. Ecological risk assessments of virus resistance transgenes must do more than survey adult plants in natural populations for the presence of the target virus. Failure to detect the virus could be due to high mortality on infection with the virus.

May, M. J., G. T. Champion, et al. (2005). "Management of genetically modified herbicide-tolerant sugar beet for spring and autumn environmental benefit." Proc Biol Sci JT - Proceedings. Biological sciences / The Royal Society. 272(1559): 111-119.

When used in genetically modified herbicide-tolerant (GMHT) crops, glyphosate provides great flexibility to manipulate weed populations with consequences for invertebrates and higher trophic levels, for example birds. A range of timings of band and overall spray treatments of glyphosate to GMHT sugar beet were compared with a conventional weed control programme in four field trials over 2 years. Single overall sprays applied between 200 and 250 accumulated day degrees (above a base air temperature of 3 degrees C; degrees Cd) and band applied treatments applied at 10% or 20% ground cover within the crop rows generally gave significantly greater weed biomass and seed rain than conventional treatments, while later band sprays (more than 650 degrees Cd) reduced seed return. Two overall sprays of glyphosate produced low weed biomass and generally lowest seed return of all treatments but tended to give some of the highest yields. However, the early overall sprays (200-250 degrees Cd) and band sprays gave as good or better yields than the conventional and were generally equivalent to the two overall-spray programme. Viable seeds in the soil after the experiment were generally higher following the early overall (200-250 degrees Cd) and the band spray treatments than following the conventional. The results show that altered management of GMHT sugar beet can provide alternative scenarios to those of the recent Farm Scale Evaluation trials. Without yield loss they can enhance weed seed banks and autumn bird food availability compared with conventional management, or provide early season benefits to invertebrates and nesting birds, depending on the system chosen. Conventional weed control does not have the flexibility to enable these scenarios that benefit both agriculture and environment, although there may be some options for increasing weed seed return in autumn.

Meagher, T. R., F. C. Belanger, et al. (2003). "Using empirical data to model transgene dispersal." Philosophical Transactions of the Royal Society of London Series B-Biological Sciences 358(1434): 1157-1162.

One element of the current public debate about genetically modified crops is that gene flow from transgenic cultivars into surrounding weed populations will lead to more problematic weeds, particularly for traits such as herbicide resistance. Evolutionary biologists can inform this debate by providing accurate estimates of gene flow potential and subsequent ecological performance of resulting hybrids. We develop a model for gene flow incorporating exponential distance and directional effects to be applied to wind-pollinated species. This model is applied to previously published data on gene flow in experimental plots of Agrostis stolonifera L. (creeping bentgrass), which assessed gene flow from transgenic plants resistant to the herbicide glufosinate to surrounding non-transgenic plants. Our results show that although pollen dispersal can be limited in some sites, it may be extensive in others, depending on local conditions such as exposure to wind. Thus, hybridization under field conditions is likely to occur. Given the nature of the herbicide resistance trait, we regard this trait as unlikely to persist in the absence of herbicide, and suggest that the ecological consequences of such gene flow are likely to be minimal.

Meilan, R., A. M. Brunner, et al. (2001). Modification of flowering in transgenic trees. Molecular Breeding of Woody Plants. N. Morohoshi and A. Komamine, Elsevier Science.

Mercer, K. L., D. A. Andow, et al. (2007). "Stress and domestication traits increase the relative fitness of crop-wild hybrids in sunflower." Ecology Letters 10(5): 383-393.

After a decade of transgenic crop production, the dynamics of gene introgression into wild relatives remain unclear. Taking an ecological genetics approach to investigating fitness in crop-wild hybrid zones, we uncovered both conditions and characteristics that may promote introgression. We compared diverse crop-wild hybrid genotypes relative to wild Helianthus annuus under one benign and three stressful agricultural environments. Whereas relative fitness of crop-wild hybrids averaged 0.25 under benign conditions, with herbicide application or competition it reached 0.45 and was more variable. In some instances, hybrid fitness matched wild fitness (approximate to 1). Thus, wild populations under agronomic stress may be more susceptible to introgression. Although 'domestication' traits are typically considered unlikely to persist in wild populations, we found some (e.g. rapid growth and early flowering) that may enhance hybrid fitness, especially in stressful environments. Rigorous assessment of how particular genotypes, phenotypes, and environments affect introgression will improve risk assessment for transgenic crops.

Mercer, K. L., D. L. Wyse, et al. (2006). "Effects of competition on the fitness of wild and crop-wild hybrid sunflower from a diversity of wild populations and crop lines." Evolution 60(10): 2044-2055.

Gene flow between crop fields and wild populations often results in hybrids with reduced fitness compared to their wild counterparts due to characteristics imparted by the crop genome. But the specifics of the evolutionary outcome of crop-wild gene flow may depend on context, varying due to local environmental conditions and genetic variation within and among wild populations and among crop lines. To evaluate context-dependence of fitness of F, hybrids, sunflower crop lines were crossed with nine wild populations from across the northern United States. These crop-wild hybrids and their wild counterparts were grown under agricultural conditions in the field with and without wheat competition. Hybrids were far less fecund than wild plants, yet more likely to survive to reproduce. There was considerable variability among wild populations for fecundity and the specific crop line used to generate the crop-wild hybrid significantly affected fecundity. The fitness deficit suffered by crop-wild hybrids varied by population, as did the rankings of the crop-wild hybrids from three different crop lines. Wheat competition decreased fecundity and survival considerably and hampered seed production of wild plants more than that of hybrids. Genotype X environment interactions indicated that the response of fitness to competition differed by population. Consequently, the fitness of hybrids relative to wild plants varied considerably among wild populations and was not consistent across environments. Notably, relative fitness of hybrids was greater under competitive conditions. This research is the first study of its kind to demonstrate that the consequences of crop-wild gene flow are context dependent and contingent on the genetics of the specific wild populations and the local biotic and abiotic conditions.

Merkle, S. A. and J. F. Dean (2000). "Forest tree biotechnology." Curr Opin Biotechnol 11(3): 298-302.

The past year has seen the fruits of biotechnological manipulation of forest trees approach commercial application. Advances in somatic embryogenesis have brought mass clonal propagation of the top commercial trees closer to reality, and efficient gene transfer systems have been developed for a number of conifers and hardwoods. Radical alterations in the quantity and quality of lignin in wood have been shown to be possible in softwoods and hardwoods through identification of naturally occurring mutants, as well as by engineering the lignin biosynthetic pathway with transgenes. The potential environmental and social impacts of the release of transgenic trees have become an increasingly contentious issue that will require more attention if we are to use these technologies to their full advantage.

Messeguer, J., C. Fogher, et al. (2001). "Field assessments of gene flow from transgenic to cultivated rice (Oryza sativa L.) using a herbicide resistance gene as tracer marker." Theoretical and Applied Genetics 103(8): 1151-1159.

Development of plant genetic engineering has led to the deployment of transgenic crops and, simultaneously, to the need for a thorough assessment of the risks associated with their environmental release. This study investigated the occurrence of gene flow from transgenic rice to non-transgenic rice plants under agronomic conditions using a herbicide resistance gene as a tracer marker. Two field experiments were established in the paddy fields of two main Mediterranean rice-growing areas of Spain and Italy. In both locations analyses of phenotypic, molecular and segregation data showed that pollination of recipient plants with pollen of the transgenic source occurred at a significant frequency. A gene flow slightly lower than 0.1% was detected in a normal side-by-side plot design. Similar results were found in a circular plot when the plants were placed at 1-m distance from the transgenic central nucleus. A strong asymmetric distribution of the gene flow was detected among this circle and highest values (0.53%) were recorded following the direction of the dominant Wind. A significant lowest value (0.01%) was found in the other circle (5 m from the transgenic plants) as was expected according to the characteristics of rice pollen. Such circular-field trial designs could also prove to be very useful in studying the gene flow to other commercial cultivars of rice with the aim of establishing strategies to prevent pollen dispersal from commercial transgenic fields to the neighbouring conventional fields.

Metz, P. L. J., E. Jacobsen, et al. (1997). "The impact on biosafety of the phosphinothricin-tolerance transgene in inter-specific B-rapa x B-napus hybrids and their successive backcrosses." Theoretical and Applied Genetics 95(3): 442-450.

There is strong evidence indicating that gene flow from transgenic B. napus into weedy wild relatives is inevitable following commercial release. Research should now focus on the transmission, stability, and impact of transgene expression after the initial hybridization event. The present study investigated the transfer of a phosphinothricin-tolerance transgene by inter-specific hybridization between B. rapa and two transgenic B. napus lines. The expression of the transgene was monitored in the F-1 hybrids and in subsequent backcross generations. The transgene was transmitted relatively easily into the F-1 hybrids and retained activity. Large differences in the transmission frequency of the transgene were noted between offspring of the two transgenic lines during backcrossing. The most plausible explanation of these results is that the line showing least transmission during backcrossing contains a transgene integrated into a C-genome chromosome. Approximately 10% of offspring retained the tolerant trait in the BC, and BC, generations. The implications of these findings for the stable introgression of transgenes carried on one of thp chromosomes of the C-genome from B. napus and into B. rapa are briefly discussed.

Michaud, D. (2005). "Environmental impact of transgenic crops. I. Transgene migration." Phytoprotection 86(2): 93-105.

The large-scale adoption of transgenic crops over the last ten years has led several groups to question the possible impacts of these new plant lines on agricultural and natural ecosystems. In particular, questions have been raised about the impact of the transgenes on the environment, and about an eventual "pollution" of the overall genetic pool of living organisms at the ecosystem level. After an introduction on the possible environmental impacts of transgenic plants, this review summarizes the current knowledge on the fate - or migration - of transgenes in the environment. Hybridization and introgression processes involving transgenic crops and their close relatives are first considered. Transgene integration in non-related organisms by horizontal gene transfer is then considered. A companion review in this same issue addresses the environmental impacts of recombinant proteins encoded by the transgenes (Michaud 2005).

Michaud, D. (2005). "Environmental impact of transgenic crops. II. Impact of recombinant traits." Phytoprotection 86(2): 107-124.

A scientific communication reporting the deleterious effects on monarch butterfly larvae of a transgenic corn hybrid expressing a Bacillus thuringiensis delta-endotoxin has caused, a few years ago, an unprecedented controversy on the environmental impact of recombinant traits introduced into the genome of agricultural crops. This review, complementing a review in this same issue on transgene migration in the environment (Michaud 2005), addresses the impact of these new traits on the development and survival of different non-target living organisms present in the environment. The impact of these new traits is first considered at the ecosystem level, in relation with the effects of current agricultural practices on field biodiversity. The impact of these traits is then considered in relation with the specific interactions established in the field or under laboratory conditions between the modified plant and a collection of model organisms including secondary herbivorous pests, predatory arthropods and different species of the soil community.

Mikkelsen, T. R., J. Jensen, et al. (1996). "Inheritance of oilseed rape (Brassica napus) RAPD markers in a backcross progeny with Brassica campestris." Theoretical and Applied Genetics 92(3-4): 492-497.

Different cultivars/transgenic lines of oilseed rape (Brassica napus) were crossed (as females) with different cultivars/populations of Brassica campestris. All cross combinations produced seed, with an average seed set per pollination of 9.8. Backcrossing of selected interspecific hybrids (as females) to B. campestris resulted in a much lower seed set, average 0.7 seed per pollination. In the single backcross progeny where a large enough population (92 plants) was obtained for analysis, 33 B. napus specific RAPD markers were investigated to determine the extent of transfer of oilseed rape genetic material into this population. Markers were transferred to the backcross generation with frequencies ranging from 26% to 91%. Almost all of the markers (30/33) were transferred in a frequency not significantly different from 50%. Analysis of the pairwise segregation of markers revealed that 23 markers could be assigned to six linkage groups, most probably reflecting six B. napus C-chromosomes. The presence of backcross plants with recombinant genotypes suggests that complex genetic processes can take place during the interspecific hybridisation and backcrossing in these Brassica species. The implications of our results for the possible choice nf integration sites of transgenes in oilseed rape are discussed.

Miller, H. I. and G. Conko (2004). "Chasing 'transgenic' shadows." Nature Biotechnology 22(6): 654-655.

MIller, T. A. (2004). "Rachel Carson and the adaptation of biotechnology to crop production." American Entomologist 50(4): 194-198.

Miller, T. A., D. J. Lampe, et al. (2007). Transgenic and paratransgenic insects in crop protection. Insecticides Design Using Advanced Technologies. I. Ishaaya, R. Nauen and A. R. Horowitz. Berlin, Heidelberg, Springer-Verlag: 87-103.

Mlynarova, L., A. J. Conner, et al. (2006). "Directed microspore-specific recombination of transgenic alleles to prevent pollen-mediated transmission of transgenes." Plant Biotechnol J 4(4): 445-452.

A major challenge for future genetically modified (GM) crops is to prevent undesired gene flow of transgenes to plant material intended for another use. Recombinase-mediated auto excision of transgenes directed by a tightly controlled microspore-specific promoter allows efficient removal of either the selectable marker gene or of all introduced transgenes during microsporogenesis. This way, transgene removal becomes an integral part of the biology of pollen maturation, not requiring any external stimulus such as chemical induction by spraying. We here show the feasibility of engineering transgenic plants to produce pollen devoid of any transgene. Highly efficient excision of transgenes from tobacco pollen was achieved with a potential failure rate of at most two out of 16,800 seeds (0.024%). No evidence for either premature activation or absence of activation of the recombinase system was observed under stress conditions in the laboratory. This approach can prevent adventitious presence of transgenes in non-GM crops or related wild species by gene flow. Such biological containment may help the deployment and management of coexistence practices to support consumer choice and will promote clean molecular farming for the production of high-value compounds in plants.

Molin, S. and S. Kjelleberg (1993). "Release of Engineered Microorganisms - Biological Containment and Improved Predictability for Risk Assessment." Ambio 22(4): 242-245.

The potential risks of unintentional releases of genetically modified organisms, and the lack of predictable behavior of these in the environment are topics which are the subject of considerable concern. This concern is accentuated in connection with the next phase of gene technology comprising deliberate releases. The possibilities of reducing such potential risks and increasing the predictability of the organisms are discussed for genetically engineered bacteria. Different approaches towards designing disabled strains without seriously reducing their beneficial effects are presented. Principally, two types of strain design are discussed: Actively contained bacteria based on the introduction of controlled suicide systems; and passively contained strains based on genetic interference with their survival under environmental stress conditions.

Moon, H. S., M. D. Halfhill, et al. (2006). "Expression of green fluorescent protein in pollen of oilseed rape (Brassica napus L.) and its utility for assessing pollen movement in the field." Biotechnology J 1(10): 1147-1152.

Transgene movement via pollen is an important component of gene flow from transgenic plants. Here, we present proof-of-concept studies that demonstrate the monitoring of short distant movement of pollen expressing a genetically encoded fluorescent tag in oilseed rape (Brassica napus L. cv. Westar). Transgenic oilseed rape plants were produced using Agrobacterium-mediated transformation method with the pBINDC1 construct containing a green fluorescent protein (GFP) variant, mGFP5-ER, under the control of the pollen-specific LAT59 promoter from tomato. Transgenic pollen was differentiated from non-transgenic pollen in vivo by a unique spectral signature, and was shown to be an effective tool to monitor pollen movement in the greenhouse and field. GFP-tagged pollen also served as a practical marker to determine the zygosity of plants. In a greenhouse pollen flow study, more pollen was captured at closer distances from the source plant plot with consistent wind generated by a fan. Under field conditions, GFP transgenic pollen grains were detected up to a distance of 15 m, the farthest distance from source plants assayed. GFP-tagged pollen was easily distinguishable from non-transgenic pollen using an epifluorescence microscope.

Moon, W. and S. K. Balasubramanian (2004). "Public attitudes toward agrobiotechnology: The mediating role of risk perceptions on the impact of trust, awareness, and outrage." Review of agricultural economics 26(2): 186-208.

Mooney, S. and D. Gerard (2003). "Using environmental bonds to regulate the risks of GM crops: problems and prospects." Environ Biosafety Res 2(1): 25-32.

We examine the characteristics and limitations of the existing system of tort liability for addressing potential environmental damages from GM crops and consider whether environmental bonding could be used to address these risks. We find that in the case of GM crops, a bonding mechanism would complement some of the strengths of tort liability. Specifically, the bonding mechanism provides some protection against bankruptcy, and also shifts the burden of risk toward life science companies that develop the technology. These factors could encourage additional early research by life science firms. However, a bonding mechanism adds to the regulatory apparatus, and would likely increase administrative costs, over tort liability, for public and private parties. Nevertheless, an attractive possibility is that the cumulative outcomes of bonding, e.g., shifting the risk burden, providing a measure of bankruptcy protection, and introducing an additional regulatory component, would mitigate some of the political and social objections to the environmental release of GM crops.

Morris, S. H. (2007). "EU biotech crop regulations and environmental risk: a case of the emperor's new clothes?" Trends Biotechnolnology 25(1): 2-6.

European Union Commissioner for the Environment Stavros Dimas recently hailed 'upgraded' non-genetically modified (GM) crops as an alternative to GM crops. A comparative analysis of the environmental risks associated with such non-GM herbicide-resistant crops and GM herbicide-resistant crops is presented here. The analysis highlights serious weaknesses in the European Union (EU) regulatory framework, and the contradictory policy of the EU Commission on the precautionary principle is also shown. The continued political stance of ignoring these regulatory and policy inconsistencies is examined and found to be flawed. It is postulated that, even in the face of these flaws and coupled with recent statements from the UK drawing attention to inconsistencies in the EU regulatory framework, the EU will continue to ignore the real and present environmental risks associated with upgraded non-GM crops for biopolitical reasons.

Morris, W. F., P. M. Kareiva, et al. (1994). "Do Barren Zones and Pollen Traps Reduce Gene Escape from Transgenic Crops." Ecological Applications 4(1): 157-165.

As genetically engineered crop varieties near widespread cultivation, both agronomic and environmental concerns mandate the development of effective strategies for isolating transgenic varieties from related non-transgenic varieties or cross-fertile weeds. We present the results of the first field experiment designed to test the effectiveness of two containment strategies that are commonly used in field trials of transgenic crops: (1) an isolation zone devoid of vegetation to discourage emigration of insect pollinators from transgenic plots; and (2) trap crops (non-transgenic varieties of the same crop planted adjacent to the transgenic plot that can ''cleanse'' emigrating pollinators of transgenic pollen). In conjunction with field trials of genetically engineered canola (Brassica napus) conducted by Calgene, Inc., in California and Georgia, we varied both the width of the barren zone and the presence or absence of a trap crop, and measured the effects on gene escape. Escape was easily detected since the genetic construct inserted into the transgenic canola contained a gene that rendered seedlings resistant to the normally lethal antibiotic kanamycin. Our results suggest that barren zones 4-8 m in width may actually increase seed contamination over what would be expected if the intervening ground were instead planted entirely with a trap crop. When trap crops occupied a limited portion of the isolation zone separating transgenic and non-transgenic varieties, the effectiveness of the trap depended on the width of the isolation zone: they reduced gene escape when the two varieties were separated by 8 m, but increased escape across a 4-m isolation zone. We conclude that, for the relatively short isolation distances we examined, the most effective strategy for reducing the escape of transgenic pollen is to devote the entire region between transgenic and non-transgenic varieties to a trap crop.

Moyes, C. L., J. M. Lilley, et al. (2002). "Barriers to gene flow from oilseed rape (Brassica napus) into populations of Sinapis arvensis." Molecular Ecology 11(1): 103-112.

One concern over growing herbicide-tolerant crops is that herbicide-tolerance genes may be transferred into the weeds they are designed to control. Brassica napus (oilseed rape) has a number of wild relatives that cause weed problems and the most widespread of these is Sinapis arvensis (charlock). Sinapis arvensis seed was collected from 102 populations across the UK, within and outside B. napus-growing areas. These populations were tested for sexual compatibility with B. napus and it was found that none of them hybridized readily in the glasshouse. In contrast to previous studies, we have found that hybrids can be formed naturally with S. arvensis as the maternal parent. Six diverse B. napus cultivars (Capricorn, Drakkar, Falcon, Galaxy, Hobson and Regent) were tested for their compatibility with S. arvensis but no cultivar hybridized readily in the glasshouse. We were unable to detect gene transfer from B. napus to S. arvensis in the field, confirming the extremely low probability of hybridization predicted from the glasshouse work.

Mp, K. v. K., E. A. Casman, et al. (2004). "Elicitation of expert judgments of uncertainty in the risk assessment of herbicide-tolerant oilseed crops." Risk Anal JT - Risk analysis : an official publication of the Society for Risk Analysis. 24(6): 1515-1527.

One of the lay public's concerns about genetically modified (GM) organisms (GMO) and related emerging technologies is that not all the important risks are evaluated or even identified yet--and that ignorance of the unanticipated risks could lead to severe environmental or public health consequences. To some degree, even the scientists who participated in the analysis of the risks from GMOs (arguably the people most qualified to critique these analyses) share some of this concern. To formally explore the uncertainty in the risk assessment of a GM crop, we conducted detailed interviews of seven leading experts on GM oilseed crops to obtain qualitative and quantitative information on their understanding of the uncertainties associated with the risks to agriculture from GM oilseed crops (canola or rapeseed). The results of these elicitations revealed three issues of potential concern that are currently left outside the scope of risk assessments. These are (1) the potential loss of the agronomic and environmental benefits of glyphosate (a herbicide widely used in no-till agriculture) due to the combined problems of glyphosate-tolerant canola and wheat volunteer plants, (2) the growing problem of seed lot contamination, and (3) the potential market impacts. The elicitations also identified two areas where knowledge is insufficient. These are: the occurrence of hybridization between canola and wild relatives and the ability of the hybrids to perpetuate themselves in nature, and the fate of the herbicide-tolerance genes in soil and their interaction with soil microfauna and -flora. The methodological contribution of this work is a formal approach to analyzing the uncertainty surrounding complex problems.

Mulder, C., M. Wouterse, et al. (2006). "Can transgenic maize affect soil microbial communities?" Plos Computational Biology 2(9): 1165-1172.

The aim of the experiment was to determine if temporal variations of belowground activity reflect the influence of the Cry1Ab protein from transgenic maize on soil bacteria and, hence, on a regulatory change of the microbial community (ability to metabolize sources belonging to different chemical guilds) and/or a change in numerical abundance of their cells. Litter placement is known for its strong influence on the soil decomposer communities. The effects of the addition of crop residues on respiration and catabolic activities of the bacterial community were examined in microcosm experiments. Four cultivars of Zea mays L. of two different isolines ( each one including the conventional crop and its Bacillus thuringiensis cultivar) and one control of bulk soil were included in the experimental design. The growth models suggest a dichotomy between soils amended with either conventional or transgenic maize residues. The Cry1Ab protein appeared to influence the composition of the microbial community. The highly enhanced soil respiration observed during the first 72 h after the addition of Bt-maize residues can be interpreted as being related to the presence of the transgenic crop residues. This result was confirmed by agar plate counting, as the averages of the colony-forming units of soils in conventional treatments were about one-third of those treated with transgenic straw. Furthermore, the addition of Bt-maize appeared to induce increased microbial consumption of carbohydrates in BIOLOG EcoPlates. Three weeks after the addition of maize residues to the soils, no differences between the consumption rate of specific chemical guilds by bacteria in soils amended with transgenic maize and bacteria in soils amended with conventional maize were detectable. Reaped crop residues, comparable to post-harvest maize straw (a common practice in current agriculture), rapidly influence the soil bacterial cells at a functional level. Overall, these data support the existence of short Bt-induced ecological shifts in the microbial communities of croplands' soils.

Munster, P. and A. M. Wieczorek (2007). "Potential gene flow from agricultural crops to native plant relatives in the Hawaiian Islands." Agriculture Ecosystems & Environment 119(1-2): 1-10.

Island populations have a much higher risk of extinction than their mainland counterparts for a number of reasons. Particular concern has been voiced that gene flow and hybridization between agricultural crops and native plant species may exacerbate their precarious position, especially if the gene flow occurs from crops developed through recombinant DNA technologies. Horizontal gene transfer (HGT) and vertical gene transfer (VGT) are the two possible ways for gene flow and introgression to occur. VGT is more likely to facilitate gene transfer between agricultural crops and native plant species, although this too is dependent on a variety of factors. In this critical review phylogenetic tribal boundaries were used as a limit to hybridization potential. Overlap was found between agricultural crops and native species in four tribes: Heliantheae. Gossypieae, Solaneae, and Phaseoleae. In each tribe the factors which increase and decrease the likelihood of hybridization were evaluated and distribution analyses performed. In general, it is concluded that hybridization potentials are low for most species (except Gossypium tomentosum that is known to hybridize with its cultivated relatives), however, small scale pollination studies should be performed for each tribe to quantify the risk and to better manage populations of native species. (c) 2006 Elsevier B.V. All rights reserved.

Murphy, J., L. Levidow, et al. (2006). "Regulatory standards for environmental risks: Understanding the US-European union conflict over genetically modified crops." Social Studies of Science 36(1): 133-160.

US and European Union (EU) approaches to the regulation of genetically modified organisms (GMOs) are often explained using the ideas of 'sound science' and the 'precautionary principle'. These stereotypes, however, can be misleading. They can conceal conflicts within jurisdictions and important interactions between them. This paper avoids these ideas and instead analyses conflicts and interactions associated with the regulation of GMOs in the USA and the EU, using the example of Bt maize - a genetically modified crop. It focuses on risk assessment as a standard-setting process, and explains changes in regulatory standards. In this case, public protest and trade conflict created an opportunity for a transatlantic network of critical scientists to challenge regulatory standards and for non-governmental organizations to press for higher ones. The paper links two analytical perspectives to account for how this happened. 'Regulatory science' helps to explain what happens when the 'private' government-industry-academia network associated with risk regulation is opened up to greater public scrutiny. It also helps to explain how the context and content of regulatory science mutually shape each other. 'Trading up' helps to explain opportunities and pressures to raise regulatory standards associated with US-EU trade liberalization and trade conflict.

Myhr, A. I. (2005). "Stretched peer-review on unexpected results (GMOs)." Water Sci Technol 52(6): 99-106.

Science is the basis for governance of risk from genetically modified organisms (GMO), and it is also a primary source of legitimacy for policy decision. However, recently the publication of unexpected results has caused controversies and challenged the way in which science should be performed, be published in scientific journals, and how preliminary results should be communicated. These studies have subsequently, after being accepted for publication within the peer-review process of leading scientific journals, been thoroughly re-examined by many actors active within the GMO debate and thereby drawn extensive media coverage. The publicized charges that the research involved does not constitute significant evidence or represent bad science have in fact deflected attention away from the important questions related to ecological and health risks raised by the research. In this paper, I will argue that unexpected findings may represent "early warnings." Although early warnings may not represent reality, such reports are necessary to inform other scientists and regulators, and should be followed up by further research to reveal the validity of the warnings. Furthermore, science that embraces robust, participatory and transparent approaches will be imperative in the future to reduce the present controversy surrounding GMO use and release.

Myhr, A. I. and T. Traavik (2003). "Genetically modified (GM) crops: Precautionary science and conflicts of interests." Journal of agricultural & environmental ethics 16(3): 227-247.

Risk governance of GM plants and GM food products is presently subject to heated scientific and public controversies. Scientists and representatives of the biotechnology industry have dominated debates concerning safety issues. The public is suspicious with regard to the motives of scientists, companies, and political institutions involved. The dilemmas posed are nested, embracing value questions, scientific uncertainty, and contextual issues. The obvious lack of data and insufficient information concerning ecological effects call for application of the Precautionary Principle (PP). There are, however, divergent opinions among scientists about the relevance of putative hazards, definition of potential "adverse effects," and whether actions should be taken to prevent harm. The reliance on the concept of substantial equivalence in safety evaluation of GM food is equally controversial. Consequently, value assumptions embedded in a scientific framework may be a barrier for employment of the PP. One of our major conclusions is that precautionary GMP usage requires risk assessment criteria yet undeveloped, as well as broader and more long-term conceptions of risk, uncertainty, and ignorance. Conflicts of interest and public participation are other issues that need to be taken into consideration. GMP governance regimes that are justifiable from a precautionary and ethical point of view must transcend traditional scientific boundaries to include alternative scientific perspectives as well as public involvement.

Nap, J.-P., P. L. J. Metz, et al. (2003). "The release of genetically modified crops into the environment. Part I. Overview of current status and regulations." Plant J 33(1): 1-18.

In the past 6 years, the global area of commercially grown, genetically modified (GM) crops has increased more than 30-fold to over 52 million hectares. The number of countries involved has more than doubled. Especially in developing countries, the GM crop area is anticipated to increase rapidly in the coming years. Despite this high adoption rate and future promises, there is a multitude of concerns about the impact of GM crops on the environment. Regulatory approaches in Europe and North America are essentially different. In the EU, it is based on the process of making GM crops; in the US, on the characteristics of the GM product. Many other countries are in the process of establishing regulation based on either system or a mixture. Despite these differences, the information required for risk assessment tends to be similar. Each risk assessment considers the possibility, probability and consequence of harm on a case-by-case basis. For GM crops, the impact of non-use should be added to this evaluation. It is important that the regulation of risk should not turn into the risk of regulation. The best and most appropriate baseline for comparison when performing risk assessment on GM crops is the impact of plants developed by traditional breeding. The latter is an integral and accepted part of agriculture.

Nijs, H. C. M. d., D. Bartsch, et al. (2004). Introgression from genetically modified plants into wild relatives.

Introgression is the incorporation of a gene from one organism complex into another as a result of hybridization. A major concern with the use of genetically modified (GM) plants is the unintentional spread of the new genes from cultivated plants to their wild relatives and the subsequent impacts on the ecology of wild plants and their associated flora and fauna. The book reviews these issues, focusing on the ecological and evolutionary effects of introducing GM cultivars. It presents a summary of the current knowledge state of crop-wild relatives hybridization and introgression, and the measurement and prediction of their consequences. As a result it represents a major contribution to the debate about the risks of GM crops and measures, such as post commercialization monitoring, required to determine the longer term impacts of GM crops on ecosystems. The book presents edited and revised presentations given at a conference of the same name, organized in January 2003 by the University of Amsterdam (Netherlands) and the Robert Koch Institute (Germany), on behalf of the European Science Foundation funded programme for Assessment of the Impacts of Genetically Modified Plants (AIGM).

NRC (2002). Environmental Effects of Transgenic Plants: The scope and adequacy of regulation. Washington, D.C., National Academy Press.

NRC (2004). Biological confinement of genetically engineered organisms. Washington, DC, National Academy of Sciences.

Executive summary only

Nurminiemi, M., J. Tufto, et al. (1998). "Spatial models of pollen dispersal in the forage grass meadow fescue." Evolutionary Ecology 12(4): 487-502.

Several bivariate probability distributions, generated by different underlying dispersal mechanisms, are fitted to the observed frequencies of an isozyme marker gene using a maximum likelihood approach. The pollen dispersal data were generated using two experimental populations of meadow fescue (Festuca pratensis Huds.), homozygous for different allozymes at the (Pgi-2) locus, arranged in a circular donor-acceptor field design. The contribution of a plant depends on plant position, fecundity and flowering time, factors which are taken into account when fitting the different models. Several approximate likelihood-ratio tests are done between alternative nested models, and a wind threshold model with bimodality in the wind direction is selected. The evolutionarily important variances and expectations of gene displacement under the selected model are calculated. It is also shown that the underlying probability distribution is significantly more than exponentially leptokurtic. By fitting a distribution of deposition in all three dimensions to the data, taking into account differences in plant height, separate estimates of additional physical parameters are obtained, showing that gravity and vertical random movements are more important than intervening vegetation in limiting pollen dispersal in meadow fescue. According to the model, plants with a high seed yield contribute pollen over-proportionally to neighbouring plants.

Oberhauser, K. S., M. D. Prysby, et al. (2001). "Temporal and spatial overlap between monarch larvae and corn pollen." Proc Natl Acad Sci U S A 98(21): 11913-11918.

To assess the likelihood that monarch larvae will be exposed to Bacillus thuringiensis (Bt) pollen, we studied milkweed and monarch densities in habitats which comprise much of the land available to breeding monarchs, e.g., cornfields, cornfield edges, other agricultural fields, and nonagricultural areas, in four regions of the monarch breeding range. We found that monarchs use milkweed in cornfields throughout their breeding season, and that per plant densities are as high or higher in agricultural habitats as in nonagricultural habitats. As a result of the prevalence of agricultural land, most of the monarchs produced in the upper Midwest are likely to originate in cornfields or other agricultural habitats. There was a greater temporal overlap between susceptible monarchs and corn anthesis in the northern than the southern part of the summer breeding range, because of earlier pollen shed in the south. The importance of agricultural habitats to monarch production suggests that, regardless of the impact of genetically modified crops, agricultural practices such as weed control and foliar insecticide use could have large impacts on monarch populations.

Obrycki, J. J., J. E. Losey, et al. (2001). "Transgenic insecticidal corn: Beyond insecticidal toxicity to ecological complexity." Bioscience 51(5): 353-361.

O'Callaghan, M., T. R. Glare, et al. (2005). "Effects of plants genetically modified for insect resistance on nontarget organisms." Annu Rev Entomol 50: 271-292.

Insect resistance, based on Bacillus thuringiensis (Bt) endotoxins, is the second most widely used trait (after herbicide resistance) in commercial genetically modified (GM) crops. Other modifications for insect resistance, such as proteinase inhibitors and lectins, are also being used in many experimental crops. The extensive testing on nontarget plant-feeding insects and beneficial species that has accompanied the long-term and wide-scale use of Bt plants has not detected significant adverse effects. GM plants expressing other insect-resistant proteins that have a broader spectrum of activity have been tested on only a limited number of nontarget species. Little is known about the persistence of transgene-derived proteins in soil, with the exception of Bt endotoxins, which can persist in soil for several months. Bt plants appear to have little impact on soil biota such as earthworms, collembolans, and general soil microflora. Further research is required on the effects of GM plants on soil processes such as decomposition. Assessment of nontarget impacts is an essential part of the risk assessment process for insect-resistant GM plants.

OECD (2001). Report of the workshop on the envionmental considerations of genetically modified trees.

OECD (2007). Consensus document on safety information on transgenic plants expressing Bacillus thuringiensis-derived insect control proteins. Series on Harmonisation of Regulatory Oversight in Biotechnology.

Oliveira, A. R., T. R. Castro, et al. (2007). "Toxicological evaluation of genetically modified cotton (Bollgard) and Dipel WP on the non-target soil mite Scheloribates praeincisus (Acari: Oribatida)." Exp Appl Acarol 41(3): 191-201.

Insecticides derived from the bacterium Bacillus thuringiensis (Bt) and plants genetically modified (GM) to express B. thuringiensis toxins are important alternatives for insect pest control worldwide. Risk assessment of B. thuringiensis toxins to non-target organisms has been extensively studied but few toxicological tests have considered soil invertebrates. Oribatid mites are one of the most diverse and abundant arthropod groups in the upper layers of soil and litter in natural and agricultural systems. These mites are exposed to the toxic compounds of GM crops or pesticides mainly when they feed on vegetal products incorporated in the soil. Although some effects of B. thuringiensis products on Acari have been reported, effects on oribatid mites are still unknown. This study investigated the effects of the ingestion of Bt cotton Bollgard and of the B. thuringiensis commercial product Dipel WP on the pantropical species Scheloribates praeincisus (Scheloribatidae). Ingestion of Bollgard and Dipel did not affect adult and immature survivorship and food consumption (estimated by number of fecal pellets produced daily) or developmental time of immature stages of S. praeincisus. These results indicate the safety of Bollgard and Dipel to S. praeincisus under field conditions where exposition is lower and other food sources besides leaves of Bt plants are available. The method for toxicological tests described here can be adapted to other species of Oribatida, consisting on a new option to risk assessment studies.

Patel, R., R. J. Torres, et al. (2005). "Genetic engineering in agriculture and corporate engineering in public debate: risk, public relations, and public debate over genetically modified crops." Int J Occup Environ Health 11(4): 428-436.

Corporations have long influenced environmental and occupational health in agriculture, doing a great deal of damage, making substantial profits, and shaping public debate to make it appear that environmental misfortunes are accidents of an otherwise well-functioning system, rather than systemic. The debate over the genetically modified (GM) crops is an example. The largest producer of commercial GM seeds, Monsanto, exemplifies the industry's strategies: the invocation of poor people as beneficiaries, characterization of opposition as technophobic or anti-progress, and portrayal of their products as environmentally beneficial in the absence of or despite the evidence. This strategy is endemic to contemporary market capitalism, with its incentives to companies to externalize health and environmental costs to increase profits.

Paul, E. M., K. Capiau, et al. (1995). "A study of gene dispersal via pollen in Nicotiana tabacum using introduced genetic markers." Journal of Applied Ecology 32(4): 875-882.

1. Agrobacterium tumefaciens was used to introduce two marker genes (kanamycin resistance and beta glucuronidase) into tobacco. 2. These plants were grown in a series of field trials each consisting of a small plot of modified plants surrounded at various distances (1 m, 10 m, 20 m) by non-modified receptor plants. 3. Capsules from these receptor plants were harvested and samples of the seed were germinated on kanamycin-containing medium in laboratory conditions, as a screen for the presence of the resistance gene. Large populations of seed could be screened in this way. 4. Using these techniques, gene flow from the 'marked' plants could easily be detected. Although there were some differences in the absolute degree of gene dispersal in the different trials, there was an overall decline in transfer as distance from the marked plants increased. 5. The potential for the use of introduced genetic markers in the study of gene flow is discussed.

Pelley, J. (2004). "Ecologists call for caution with engineered organisms." Environ Sci Technol 38(10): 174A-175A.

Pertl, M., T. P. Hauser, et al. (2002). "Male fitness of oilseed rape (Brassica napus), weedy B-rapa and their F-1 hybrids when pollinating B-rapa seeds." Heredity 89: 212-218.

The likelihood that two species hybridise and backcross may depend strongly on environmental conditions, and possibly on competitive interactions between parents and hybrids. We studied the paternity of seeds produced by weedy Brassica rapa growing in mixtures with oilseed rape (B. napus) and their F-1 hybrids at different frequencies and densities. Paternity was determined by the presence of a transgene, morphology, and AFLP markers. In addition, observations of flower and pollen production, and published data on pollen fertilisation success, zygote survival, and seed germination, allowed us to estimate an expected paternity. The frequency and density of B. napus, B. rapa, and F-1 plants had a strong influence on flower, pollen, and seed production, and on the paternity of B. rapa seeds. Hybridisation and backcrossing mostly occurred at low densities and at high frequencies of B. napus and F-1, respectively. F-1 and backcross offspring were produced mainly by a few B. rapa mother plants. The observed hybridisation and backcrossing frequencies were much lower than expected from our compilation of fitness components. Our results show that the male fitness of B. rapa, B. napus, and F-1 hybrids is strongly influenced by their local frequencies, and that male fitness of F-1 hybrids, when pollinating B. rapa seeds, is low even when their female fitness (seed set) is high.

Peterson, R. K. and L. M. Shama (2005). "A comparative risk assessment of genetically engineered, mutagenic, and conventional wheat production systems." Transgenic Res JT - Transgenic research. 14(6): 859-875.

Wheat (Triticum aestivum L.) varieties produced using modern biotechnologies, such as genetic engineering and mutagenic techniques, have lagged behind other crop species, but are now being developed and, in the case of mutagenic wheat, commercially grown around the world. Because these wheat varieties have emerged recently, there is a unique opportunity to assess comparatively the potential environmental risks (human health, ecological, and livestock risks) associated with genetically engineered, mutagenic, and conventional wheat production systems. Replacement of traditional herbicides with glyphosate in a glyphosate-tolerant (genetically engineered) wheat system or imazamox in an imidazolinone-tolerant (mutagenic) wheat system may alter environmental risks associated with weed management. Additionally, because both systems rely on plants that express novel proteins, the proteins and plants themselves may impose risks. The purpose of our study was to examine comparatively the multiple aspects of risk associated with different wheat production systems in the US and Canada using the risk assessment paradigm. Specifically, we used tier 1 quantitative and qualitative risk assessment methods to compare specific environmental risks associated with the different wheat production systems. Both glyphosate and imazamox present lower human health and ecological risks than many other herbicides associated with conventional wheat production systems evaluated in this study. The differences in risks were most pronounced when comparing glyphosate and imazamox to herbicides currently with substantial market share. Current weight-of-evidence suggests that the transgenic CP4 EPSPS protein present in glyphosate-tolerant wheat poses negligible risk to humans, livestock, and wildlife. Risk for mutated AHAS protein in imidazolinone-tolerant wheat most likely would be low, but there are not sufficient effect and exposure data to adequately characterize risk. Environmental risks for herbicides were more amenable to quantitative assessments than for the transgenic CP4 EPSPS protein and the mutated AHAS protein.

Pew Initiative (2002). Three years later: Genetically engineered corn and the Monarch butterfly.

Pierre, J. and M. H. Pham-Delegue (2000). "How to study the impact of genetically modified colza on bees?" Ocl-Oleagineux Corps Gras Lipides 7(4): 341-344.

Different methods are used to study the incidence of genetically modified oilseed rape on honeybees, that depend on the type of transgene and on the transformation induced in the plant. Two examples are chosen to present risk assessment procedures. One deals with oilseed rape resistant to pest insects (by expressing protease inhibitors PI), the other concerns oilseed rape tolerant to an herbicide (glufosinate). In the first case, the aim is to ensure the safety of honeybees. First, the occurrence of the transgene product in nectar and pollen is checked and the foraging behaviour on the plants is observed Second, the effects of various concentrations, equal or higher than those expressed in the plant, is evaluated under laboratory conditions. Thus, acute and chronic toxicity, individual learning behaviour and life span of workers exposed to the PI is investigated. Experiments are also carried out to examine the effects on the colony activity and development. In addition, indirect effect related to secondary changes in plant signals cueing bees visits are examined in the second case, the aim is to assess the risk for transgene dispersal in the environment, mediated by honeybees, It is unlikely that tolerance to herbicide has toxic effects, but a pleitropic effect of the transgene could effect the value and attractiveness of the plants. So, pollen and nectar production, flower size and density are evaluated and experiments are carried out in the field to study the foraging behaviour In particular, the ability of honeybees to cross- visit transgenic and traditional oilseed rape or oilseed rape and weedy relatives is observed. Both types of studies show how complementary methods and collaborations between teams have been designed to study various aspects of the impact of genetic engineered oilseed rape on honeybees.

Pilson, D. and H. R. Prendeville (2004). "Ecological effects of transgenic crops and the escape of transgenes into wild populations." Annual Review of Ecology Evolution and Systematics 35: 149-174.

Ecological risks associated with the release of transgenic crops include nontarget effects of the crop and the escape of transgenes into wild populations. Nontarget effects can be of two sorts: (a) unintended negative effects on species that do not reduce yield and (b) greater persistence of the crop in feral populations. Conventional agricultural methods, such as herbicide and pesticide application, have large and well-documented nontarget effects. To the extent that transgenes have more specific target effects, transgenic crops may have fewer nontarget effects. The escape of transgenes into wild populations, via hybridization and introgression, could lead to increased weediness or to the invasion of new habitats by the wild population. In addition, native species with which the wild plant interacts (including herbivores, pathogens, and other plant species in the community) could be negatively affected by "transgenic-wild" plants. Conventional crop alleles have facilitated the evolution of increased weediness in several wild populations. Thus, some transgenes that allow plants to tolerate biotic and abiotic stress (e.g., insect resistance, drought tolerance) could have similar effects.

Pilson, D., A. A. Snow, et al. (2002). Fitness and population effects of gene flow from transgenic sunflower to wild Helianthus annuus. Ecological and Agronomic Consequences of Gene Flow from Transgenic Crops to Wild Relatives, The Ohio State University, Columbus, Ohio.

Pleasants, J. M., R. L. Hellmich, et al. (2001). "Corn pollen deposition on milkweeds in and near cornfields." Proc Natl Acad Sci U S A 98(21): 11919-11924.

The density of corn pollen on leaves of milkweed plants inside and outside of cornfields was measured in several studies from different localities. The purpose was to obtain a representative picture of naturally occurring pollen densities to provide a perspective for laboratory and field studies of monarch larvae feeding on milkweed leaves with Bt corn pollen. Pollen density was highest (average 170.6 grains per cm(2)) inside the cornfield and was progressively lower from the field edge outward, falling to 14.2 grains per cm(2) at 2 m. Inside the cornfield, and for each distance from the field edge, a frequency distribution is presented showing the proportion of leaf samples with different pollen densities. Inside cornfields, 95% of leaf samples had pollen densities below 600 grains per cm(2) and the highest pollen density observed was 1400 grains per cm(2), which occurred in a study with a rainless anthesis period. All other studies had rainfall events during the anthesis period. A single rain event can remove 54-86% of the pollen on leaves. Leaves on the upper portion of milkweed plants, where young monarch larvae tend to feed, had only 30-50% of the pollen density levels of middle leaves.

Pline-Srnic, W. (2005). "Technical performance of some commercial glyphosate-resistant crops." Pest Manag Sci JT - Pest management science. 61(3): 225-234.

Glyphosate-resistant (GR) crops have been sold commercially in the USA since 1996. The use of glyphosate alone or with conventional pre- and post-emergence herbicides with different modes of action gives growers many options for affordable, safe, easy, effective wide-spectrum weed control. Despite the overwhelming popularity of this technology, technical issues have surfaced from time to time as US growers adopt these crops for use on their farms. The types of concern raised by growers vary from year to year depending on the crop and the environment, but include perceptions of increased sensitivity to diseases, increased fruit abortion, reduced pollination efficiency, increased sensitivity to environmental stress, and differences in yield and agronomic characteristics between transgenic and sister conventional varieties. Although several glyphosate-resistant crops are commercially available, maize, soybean and cotton constitute the largest cultivated acreage and have likewise been associated with the highest number of technical concerns. Because glyphosate is rapidly translocated to and accumulates in metabolic sink tissues, reproductive tissues and roots are particularly vulnerable. Increased sensitivity to glyphosate in reproductive tissues has been documented in both glyphosate-resistant cotton and maize, and results in reduced pollen production and viability, or increased fruit abortion. Glyphosate treatments have the potential to affect relationships between the GR crop, plant pathogens, plant pests and symbiotic micro-organisms, although management practices can also have a large impact. Despite these potential technical concerns, this technology remains popular, and is a highly useful tool for weed control in modern crop production.

Pohl-Orf, M., U. Brand, et al. (1999). "Overwintering of genetically modified sugar beet, Beta vulgaris L. subsp vulgaris, as a source for dispersal of transgenic pollen." Euphytica 108(3): 181-186.

The potential impact of transgenic crops on community ecology will depend on the distribution and establishment of the new transgenic traits, on the sexual transfer of their new genes to the environment (Bartsch & Pohl-Orf, 1996) and on the potential ecological impact of the transgenic trait. Flowering and pollen dispersal is important for outcrossing of the genetically engineered trait. For a biennial plant, like the cultivars of Beta vulgaris L., overwintering is normally necessary to become generative and to produce pollen and seeds (Abe et al., 1997), which usually does not happen with sugar beet as a field crop harvested in autumn (Longden 1989). The starting point for the project was a transgenic sugar beet, Beta vulgaris L. subsp. vulgaris (Lange et al., 1998), with rhizomania and herbicide (Basta (R), Liberty (R)) resistance. Cold tolerance is one of the most important factors for survival of sugar beet in Central- and North-Europe. Among other ways, spreading of transgenic traits into weed beet (Boudry et al., 1993) or wild beet can occur if genetically engineered - biennial - plants survive the winter, flower in spring and spread their pollen. Field experiments were performed with transgenic breeding lines and their hybrids, transgenic and non-transgenic hybrids with Swiss chard and three conventional beet cultivars to evaluate winter survival rates at seven different field sites. We could show that survival of sugar beet - transgenic as well as conventional ones - in Germany and at the Dutch border is possible. Survival rates were well correlated with temperature data and were unexpectedly high. Differences between sugar beet hybrids and breeding lines could be detected but not within different breeding lines or hybrids. There were no differences detectable between transgenic and non-transgenic plants. The data are crucial for the risk assessment of the release of transgenic sugar beet and are the basis for further experiments towards outcrossing and establishment.

Pollack, A. (2007). U.S. Agency Violated Law in Seed Case, Judge Rules. NY Times. New York.

Pool, R. and J. Esnayra (2001). Ecological Monitoring of Genetically Modified Crops: A workshop summary. Washington, DC, National Research Council: 45.

Poppy, G. M. (2004). "Geneflow from GM plants--towards a more quantitative risk assessment." Trends Biotechnol 22(9): 436-438.

Assessing the risks associated with geneflow from GM crops to wild relatives is a significant scientific challenge. Most researchers have focused on assessing the frequency of gene flow, too often on a localized scale, and ignoring the hazards caused by geneflow. To quantify risk, multi-disciplinary research teams need to unite and scale up their studies.

Ramessar, K., A. Peremarti, et al. (2007). "Biosafety and risk assessment framework for selectable marker genes in transgenic crop plants: a case of the science not supporting the politics." Transgenic Res 16(3): 261-280.

Selectable marker gene systems are vital for the development of transgenic crops. Since the creation of the first transgenic plants in the early 1980s and their subsequent commercialization worldwide over almost an entire decade, antibiotic and herbicide resistance selectable marker gene systems have been an integral feature of plant genetic modification. Without them, creating transgenic crops is not feasible on purely economic and practical terms. These systems allow the relatively straightforward identification and selection of plants that have stably incorporated not only the marker genes but also genes of interest, for example herbicide tolerance and pest resistance. Bacterial antibiotic resistance genes are also crucial in molecular biology manipulations in the laboratory. An unprecedented debate has accompanied the development and commercialization of transgenic crops. Divergent policies and their implementation in the European Union on one hand and the rest of the world on the other (industrialized and developing countries alike), have resulted in disputes with serious consequences on agricultural policy, world trade and food security. A lot of research effort has been directed towards the development of marker-free transformation or systems to remove selectable markers. Such research has been in a large part motivated by perceived problems with antibiotic resistance selectable markers; however, it is not justified from a safety point of view. The aim of this review is to discuss in some detail the currently available scientific evidence that overwhelmingly argues for the safety of these marker gene systems. Our conclusion, supported by numerous studies, most of which are commissioned by some of the very parties that have taken a position against the use of antibiotic selectable marker gene systems, is that there is no scientific basis to argue against the use and presence of selectable marker genes as a class in transgenic plants.

Rask, M. (2006). "Closure in risk debates: Pre-assessment of Finnish forest biotechnology [electronic resource]." Technological forecasting and social change 73: 705-730.

Raybould, A. and I. Cooper (2005). "Tiered tests to assess the environmental risk of fitness changes in hybrids between transgenic crops and wild relatives: the example of virus resistant Brassica napus." Environ Biosafety Res 4(3): 127-140.

Over the last 20 years, there has been much research aimed at improving environmental risk assessment of transgenic crops. Despite large amounts of data, decisions to allow or prohibit the release of transgenic crops remain confused and controversial. We argue that part of the reason for confusion is the lack of clear definitions of components of the environment that should be protected, and, as a consequence, there is no way to judge the relevance of data collected under the auspices of 'environmental risk assessment'. Although this criticism applies to most aspects of environmental risk assessment of transgenic crops, it is most pertinent to effects that might result from an increase in plant fitness, often referred to as increased weediness. Environmental risk assessment of weediness is regarded as complicated: an increase in the fitness of a transgenic plant compared with non-transgenic counterparts will be the result of an interaction between the altered plant phenotype and an enormous number of environmental variables. This has led to the idea that risk assessment of weediness needs to "understand" these interactions, with the implication that exhaustive data are required. Here we argue that environmental risk assessment of the weediness of transgenic plants need not be complicated. Analysis of the conditions that must be met for increased weediness to occur suggests a series of studies that starts with simple tests in the laboratory under "worst case" assumptions, and becomes increasingly complex and realistic should the simpler studies not indicate negligible risk with sufficient certainty. We illustrate how the approach might work for assessing the risks of increased weediness using the example of possible introgression of a gene for Turnip mosaic virus (TuMV) resistance from oilseed rape to certain wild Brassica species.

Raybould, A. F., R. J. Mogg, et al. (1996). "The genetic structure of Beta vulgaris ssp maritima (sea beet) populations: RFLPs and isozymes show different patterns of gene flow." Heredity 77: 245-250.

Genetic variation in 12 populations of sea beet was assessed at nine isozyme and seven RFLP loci. Mean observed heterozygosity, diversity index and number of alleles per locus were not significantly different between the two classes of marker. The genetic structure of 10 of the populations was analysed using seven of the isozymes and six of the RFLPs. F-ST values between all pairs of populations were calculated separately for the isozymes and RFLPs. F-ST values were converted to amounts of gene flow (Nm) between populations under the assumptions of an island model. A regression of log Nm against log distance was used to test for isolation by distance. Mantel tests showed a highly significant decrease in Nm with distance for RFLPs but not for isozymes. It is suggested that uniform balancing selection may operate to maintain approximately equal allele frequencies among populations at the isozyme loci. If this is true then isozymes may be unsuitable for modelling the spread of neutral transgenes.

Reboud, X. (2003). "Effect of a gap on gene flow between otherwise adjacent transgenic Brassica napus crops." Theoretical and Applied Genetics 106(6): 1048-1058.

Gene flow resulting from cross pollination becomes an issue when transgenic crops are involved and the genetic modification carries a trait of ecological importance. As crop fields are often separated by a barren gap, such as an intervening roadway or unplanted area, I measured cross contamination between two herbicide-resistant transgenic fields (canola, Brassica napus) across a gap of up to 12 m. I focused on pollen exchange from the field border up to 7 m inside each field over two seasons. In the absence of a gap, I found that gene dispersal diminished rapidly with distance, with more than 40% of transgenic progeny found within the first meter from the edge of the adjacent crop. Cross contamination between fields declined more rapidly when there were intervening plants, however. Plants separated from the transgenic source by a gap of 3-4 m, yielded the same level of transgenic progeny as those separated by 1 m of crop. Both insects and wind pollinate canola, and so the explanation for my observations could involve the influence of gaps on wind patterns or on the behaviour of pollinators. The gap effect does not seem to depend only upon the variation in the density of neighbours that surrounds those plants at the crop edge versus those in the crop matrix. On the basis of this study, it is recommended that economic profit would be maximised by removing field borders after flowering rather than by leaving a surrounding gap, which would need to occupy up to threefold as much field surface to achieve the same level of containment.

Regan, H. M., R. Akcakaya, et al. (2003). "Treatments of uncertainty and variability in ecological risk assessment of single-species populations." Hum Ecol Risk Assess 9(4): 889-906.

The selection of the most appropriate model for an ecological risk assessment depends on the application, the data and resources available, the knowledge base of the assessor, the relevant endpoints, and the extent to which the model deals with uncertainty. Since ecological systems are highly variable and our knowledge of model input parameters is uncertain, it is important that models include treatments of uncertainty and variability, and that results are reported in this light. In this paper we discuss treatments of variation and uncertainty in a variety of population models. In ecological risk assessments, the risk relates to the probability of an adverse event in the context of environmental variation. Uncertainty relates to ignorance about parameter values, e.g., measurement error and systematic error. An assessment of the full distribution of risks, under variability and parameter uncertainty, will give the most comprehensive and flexible endpoint. In this paper we present the rationale behind probabilistic risk assessment, identify the sources of uncertainty relevant for risk assessment and provide an overview of a range of population models. While all of the models reviewed have some utility in ecology, some have more comprehensive treatments of uncertainty than others. We identify the models that allow probabilistic assessments and sensitivity analyses, and we offer recommendations for further developments that aim towards more comprehensive and reliable ecological risk assessments for populations.

Reichman, J. R., L. S. Watrud, et al. (2006). "Establishment of transgenic herbicide-resistant creeping bentgrass (Agrostis stolonifera L.) in nonagronomic habitats." Mol Ecol 15(13): 4243-4255.

Concerns about genetically modified (GM) crops include transgene flow to compatible wild species and unintended ecological consequences of potential transgene introgression. However, there has been little empirical documentation of establishment and distribution of transgenic plants in wild populations. We present herein the first evidence for escape of transgenes into wild plant populations within the USA; glyphosate-resistant creeping bentgrass (Agrostis stolonifera L.) plants expressing CP4 EPSPS transgenes were found outside of cultivation area in central Oregon. Resident populations of three compatible Agrostis species were sampled in nonagronomic habitats outside the Oregon Department of Agriculture control area designated for test production of glyphosate-resistant creeping bentgrass. CP4 EPSPS protein and the corresponding transgene were found in nine A. stolonifera plants screened from 20,400 samples (0.04 +/- 0.01% SE). CP4 EPSPS-positive plants were located predominantly in mesic habitats downwind and up to 3.8 km beyond the control area perimeter; two plants were found within the USDA Crooked River National Grassland. Spatial distribution and parentage of transgenic plants (as confirmed by analyses of nuclear ITS and chloroplast matK gene trees) suggest that establishment resulted from both pollen-mediated intraspecific hybridizations and from crop seed dispersal. These results demonstrate that transgene flow from short-term production can result in establishment of transgenic plants at multi-kilometre distances from GM source fields or plants. Selective pressure from direct application or drift of glyphosate herbicide could enhance introgression of CP4 EPSPS transgenes and additional establishment. Obligatory outcrossing and vegetative spread could further contribute to persistence of CP4 EPSPS transgenes in wild Agrostis populations, both in the presence or absence of herbicide selection.

Rhee, G. S., D. H. Cho, et al. (2005). "Multigeneration reproductive and developmental toxicity study of bar gene inserted into genetically modified potato on rats." J Toxicol Environ Health A 68(23-24): 2263-2276.

Each specific protein has an individual gene encoding it, and a foreign gene introduced to a plant can be used to synthesize a new protein. The identification of potential reproductive and developmental toxicity from novel proteins produced by genetically modified (GM) crops is a difficult task. A science-based risk assessment is needed in order to use GM crops as a conventional foodstuff. In this study, the specific characteristics of GM food and low-level chronic exposure were examined using a five-generation animal study. In each generation, rats were fed a solid pellet containing 5% GM potato and non-GM potato for 10 wk prior to mating in order to assess the potential reproductive and developmental toxic effects. In the multigeneration animal study, there were no GM potato-related changes in body weight, food consumption, reproductive performance, and organ weight. Polymerase chain reaction (PCR) was carried out using extracted genomic DNA to examine the possibility of gene persistence in the organ tissues after a long-term exposure to low levels of GM feed. In each generation, the gene responsible for bar was not found in any of the reproductive organs of the GM potato-treated male and female rats, and the litter-related indexes did not show any genetically modified organism (GMO)-related changes. The results suggest that genetically modified crops have no adverse effects on the multigeneration reproductive-developmental ability.

Richardson, D. M. (1998). "Forestry trees as invasive aliens." Conserv Biol 12(1): 18-26.

Rieger, M. A., M. Lamond, et al. (2002). "Pollen-mediated movement of herbicide resistance between commercial canola fields." Science JT - Science. 296(5577): 2386-2388.

There is considerable public and scientific debate for and against genetically modified (GM) crops. One of the first GM crops, Brassica napus (oilseed rape or canola) is now widely grown in North America, with proposed commercial release into Australia and Europe. Among concerns of opponents to these crops are claims that pollen movement will cause unacceptable levels of gene flow from GM to non-GM crops or to related weedy species, resulting in genetic pollution of the environment. Therefore, quantifying pollen-mediated gene flow is vital for assessing the environmental impact of GM crops. This study quantifies at a landscape level the gene flow that occurs from herbicide-resistant canola crops to nearby crops not containing herbicide resistance genes.

Rieseberg, L. H., M. J. Kim, et al. (1999). "Introgression between the cultivated sunflower and a sympatric wild relative, Helianthus petiolaris (Asteraceae)." International Journal of Plant Sciences 160(1): 102-108.

High rates of hybridization and introgression have been reported between the cultivated sunflower and its wild progenitor (both Helianthus annuus), raising concerns that neutral or favorable transgenes might escape and persist in wild H. annuus populations. However, little consideration has been given to the possibility that other wild sunflower species may hybridize with the cultivated sunflower. Here, we estimate the frequency of hybridization and introgression between the cultivated sunflower and Helianthus petiolaris, a closely related wild species whose range almost completely overlaps that of the cultivated sunflower in the central and northern plains and which hybridizes extensively with wild H. annuus. Assays of 21 cultivar-specific AFLP (amplified fragment length polymorphism) markers in 159 individuals from four sympatric populations of H. petiolaris revealed low rates of introgression, with average marker frequencies per population ranging from 0.006 to 0.026. Twenty-seven individuals had a hybrid ancestry, and all hybrids appeared to represent later- generation backcrosses. There was significant heterogeneity in rates of introgression for different markers, and eight of the 21 markers failed to introgress into any of the four populations. This and other evidence indicate that the H. petiolaris genome may be differentially permeable to introgression. These data indicate that (1) beneficial and neutral transgenes will take much longer to move into H. petiolaris populations than into wild H. annuus; (2) the risk of escape may depend on the genomic location of the transgene; and (3) escape is likely to be sporadic, occurring in some populations and not others and at different times. Thus, risk assessment in wild H. annuus is of more immediate concern than in H. petiolaris.

Rieseberg, L. H., A. Widmer, et al. (2003). "The genetic architecture necessary for transgressive segregation is common in both natural and domesticated populations." Philosophical Transactions of the Royal Society of London Series B-Biological Sciences 358(1434): 1141-1147.

Segregating hybrids often exhibit phenotypes that are extreme or novel relative to the parental lines. This phenomenon is referred to as transgressive segregation, and it provides a mechanism by which hybridization might contribute to adaptive evolution. Genetic studies indicate that transgressive segregation typically results from recombination between parental taxa that possess quantitative trait loci (QTLs) with antagonistic effects (i.e. QTLs with effects that are in the opposite direction to parental. differences for those traits). To assess whether this genetic architecture is common, we tabulated the direction of allelic effects for 3252 QTLs from 749 traits and 6 studies. Most traits (63.6%) had at least one antagonistic QTL, indicating that the genetic substrate for transgressive segregation is common. Plants had significantly more antagonistic QTLs than animals, which agrees with previous reports that transgressive segregation is more common in plants than in animals. Likewise, antagonistic QTLs were more frequent in intra- than in interspecific crosses and in morphological than in physiological traits. These results indicate that transgressive segregation provides a general mechanism for the production of extreme phenotypes at both above and below the species level and testify to the possible creative part of hybridization in adaptive evolution and speciation.

Rischer, H. and K.-M. Oksman-Caldentey (2006). "Unintended effects in genetically modified crops: revealed by metabolomics?" Trends Biotechnol 24(3): 102-104.

In Europe the commercialization of food derived from genetically modified plants has been slow because of the complex regulatory process and the concerns of consumers. Risk assessment is focused on potential adverse effects on humans and the environment, which could result from unintended effects of genetic modifications: unintended effects are connected to changes in metabolite levels in the plants. One of the major challenges is how to analyze the overall metabolite composition of GM plants in comparison to conventional cultivars, and one possible solution is offered by metabolomics. The ultimate aim of metabolomics is the identification and quantification of all small molecules in an organism; however, a single method enabling complete metabolome analysis does not exist. Given a comprehensive extraction method, a hierarchical strategy--starting with global fingerprinting and followed by complementary profiling attempts--is the most logical and economic approach to detect unintended effects in GM crops.

Ritala, A., A. M. Nuutila, et al. (2002). "Measuring gene flow in the cultivation of transgenic barley." Crop Science 42(1): 278-285.

Genetic engineering is becoming a useful tool in the improvement of plants and plant-based raw materials. Varieties with value-added traits are developed for nonfood use in industrial and medical production, and different production lines must be kept separate. For good management practices, knowledge of relevant gene flow parameters is required. In the present study, pollen-mediated dispersal of transgenes via cross-fertilization was examined. A transgenic barley (Hordeum vulgare L.) line carrying a marker gene coding for neomycin phosphotransferase 11 (nptII) was used as a pollen donor. For maximum resolution, a cytoplasmically male-sterile barley line was utilized as recipient and the flow of nptII transgene was monitored at distances of 1, 2, 3, 6, 12, 25, 50, and 100 m from the donor plots of 225 and 2000 m(2). Male-fertile plots at a distance of I m were included to measure the transgene flow in normal barley. The number of seeds obtained from male- sterile heads diminished rapidly with distance and only a few seeds ss ere found at distances of 50 and 100 m. Molecular genetic analysis (polymerase chain reaction-PCR) revealed that all seeds obtained from male-sterile heads at a distance of I m were transgenic, as anticipated. However, only 3% of the distant seeds (50 m) actually carried the transgene, whereas most of them resulted from fertilization with nontransgenic background pollen. This background pollen was mainly due to pollen leakage in some male-sterile heads. In normal male- fertile barley, the cross-fertilization frequency with transgenic pollen varied from 0 to 7% at a distance of I m. 0 depending on weather condition, on the heading day. We conclude that, because of competing self-produced and nontransgenic background pollen, the possibility of cross-pollination is very low between a transgenic barley field and an adjacent field cultivated with normal barley. However, adequate isolation distances and best management practices are needed for cultivation of transgenic barley.

Rognli, O. A., N. O. Nilsson, et al. (2000). "Effects of distance and pollen competition on gene flow in the wind-pollinated grass Festuca pratensis Huds." Heredity 85(6): 550-560.

Pollen dispersal and gene flow in the grass meadow fescue (Festuca pratensis Huds.) were studied using two populations which were homozygous for different allozymes at the Gpi-2 locus. The populations were established in a concentric donor- acceptor field experiment. Gene flow was found mainly to be affected by the distance between the donor and acceptor plants. Analysing 21 132 acceptor plant progenies, gene flow was shown to decrease rapidly with distance to the donor field up to 75 m, and beyond this distance much more slowly. The ability of donor pollen to fertilize acceptor plants depended very much on the density of the acceptor plants. Pairs of acceptor plants produced more compatible pollen locally, and captured significantly less donor pollen than single-plants. Despite the higher seed production of acceptor plants planted in pairs, the absolute number of heterozygous seeds carrying the donor allele was always lower than for single-plants, Wind direction had only a slight effect upon the type of pollen captured. Because of pollen production within the two plant populations being continuous and overlapping, the time when anthesis occurred had little effect on gene flow between the populations. Vigorous and tall acceptor plants with many panicles, high seed yield and high 1000-seed weight were able to capture more donor pollen than shorter plants. The results may be used to assess the risk of gene flow and to develop strategies for monitoring the spread of transgenes from genetically modified grasses.

Romeis, J., M. Meissle, et al. (2006). "Transgenic crops expressing Bacillus thuringiensis toxins and biological control." Nat Biotechnol 24(1): 63-71.

The area devoted to growing transgenic plants expressing insecticidal Cry proteins derived from Bacillus thuringiensis (Bt) is increasing worldwide. A major concern with the adoption of Bt crops is their potential impact on nontarget organisms including biological control organisms. Regulatory frameworks should advocate a step-wise (tiered) approach to assess possible nontarget effects of Bt crops. Laboratory and glasshouse studies have revealed effects on natural enemies only when Bt-susceptible, sublethally damaged herbivores were used as prey or host, with no indication of direct toxic effects. Field studies have confirmed that the abundance and activity of parasitoids and predators are similar in Bt and non-Bt crops. In contrast, applications of conventional insecticides have usually resulted in negative impacts on biological control organisms. Because Bt-transgenic varieties can lead to substantial reductions in insecticide use in some crops, they can contribute to integrated pest management systems with a strong biological control component.

Ronald, P. and S. Strauss (2005). Perspective: Moving the debate on genetically engineered crops forward. ASPB Newsletter.

Rong, J., B.-R. Lu, et al. (2007). "Dramatic reduction of crop-to-crop gene flow within a short distance from transgenic rice fields." New Phytol 173(2): 346-353.

* Genetically modified (GM) rice with enhanced agronomic traits and pharmaceutical uses are ready for widespread adoption. Little is known about isolation requirements for achieving stringent transgene confinement in rice. To investigate the extent of pollen-mediated crop-to-crop transgene flow, we conducted a field experiment with four plot-size treatments of adjacent GM and nonGM rice (Oryza sativa) in China. * Three insect-resistant GM rice (Bt/CpTI) and nonGM isogenic lines were used in the study. The hygromycin-resistance transgene (hpt) marker was used to screen seeds from the nonGM rice rows at different distance intervals from GM rice plots. * Based on the examination of > 2.1 million germinated seeds, we found a dramatic reduction in transgene frequencies with increasing distance from the GM crop, ranging from c. 0.28% at 0.2 m to < 0.01% at 6.2 m. In addition, different plot size did not significantly affect the frequencies of gene flow. * In conclusion, pollen-mediated crop-to-crop transgene flow in rice can be maintained at negligible levels with short spatial isolation. The model can also be applied to other crops with self- and wind-pollination.

Rosi-Marshall, E. J., J. L. Tank, et al. (2007). "Toxins in transgenic crop byproducts may affect headwater stream ecosystems." Proceedings of the National Academy of Sciences: 0707177104.

Corn (Zea mays L.) that has been genetically engineered to produce the Cry1Ab protein (Bt corn) is resistant to lepidopteran pests. Bt corn is widely planted in the midwestern United States, often adjacent to headwater streams. We show that corn byproducts, such as pollen and detritus, enter headwater streams and are subject to storage, consumption, and transport to downstream water bodies. Laboratory feeding trials showed that consumption of Bt corn byproducts reduced growth and increased mortality of nontarget stream insects. Stream insects are important prey for aquatic and riparian predators, and widespread planting of Bt crops has unexpected ecosystem-scale consequences.

Ruane, J. and A. Sonnino (2006). Results from the FAO biotechnology forum. Rome, Italy, FAO: 1-152.

Three of the conferences were devoted exclusively to GMOs, two to biotechnology in

general (including GMOs) and one to the use of molecular markers. Two conferences were held

each year in 2002 and 2003 and one each in 2004 and 2005. All six conferences were

multisectorial, covering the use of biotechnology in animals, crops, fish and forest trees.

The dates and titles were:

• Conference 7 (31 May to 6 July 2002): Gene flow from GM to non-GM populations

in the crop, forestry, animal and fishery sectors.

• Conference 8 (13 November to 16 December 2002): What should be the role and

focus of biotechnology in the agricultural research agendas of developing countries?

• Conference 9 (28 April to 1 June 2003): Regulating GMOs in developing and

transition countries.

• Conference 10 (17 November to 14 December 2003): Molecular marker-assisted

selection as a potential tool for genetic improvement of crops, forest trees, livestock

and fish in developing countries.

• Conference 11 (14 June to 15 July 2004): Biotechnology applications in food

processing: Can developing countries benefit?

• Conference 12 (17 January to 13 February 2005): Public participation in decisionmaking

regarding GMOs in developing countries: How to effectively involve rural

people.

Ryan, E., E. Mullins, et al. (2006). "Tracing field hybridization in Ryegrass species using microsatellite and morphological markers." Environ Biosafety Res 5(2): 111-117.

We have assessed the utility of morphological and microsatellite markers for tracing field hybridization between Lolium multiflorum and Lolium perenne in cereal-enclosed gene flow plots. The presence of awns on the inflorescence of F(1) hybrids was found to be a reliable, but underscoring, indicator of L. multiflorum paternity in L. perenne derived seed as determined by inheritance of species-specific alleles at the microsatellite locus 'H01 H06' in these progeny. A positive correlation was evident in the experimental treatment between the number of pollen donor plants in a given plot and the frequency of hybrid F(1) seed harvested from pollen receptor plants in that plot. These experiments have established the utility of naturally occurring heritable markers for the measurement of gene flow rates in field Ryegrass populations, with particular significance for risk assessment modeling of potential gene flow from transgenic grass cultivars.

Saeglitz, C., M. Pohl, et al. (2000). "Monitoring gene flow from transgenic sugar beet using cytoplasmic male-sterile bait plants." Molecular Ecology 9(12): 2035-2040.

One of the most discussed environmental effects associated with the use of transgenic plants is the flow of genes to plants in the environment. The flow of genes may occur through pollen since it is the reproductive system that is designed for gene movement. Pollen-mediated gene escape is hard to control in mating plants. Pollen from a wind pollinator can move over distances of more than 1000 m. To investigate the efficiency of transgenic pollen movement under realistic environmental conditions, the use of bait plants might be an effective tool. In this study, cytoplasmic male-sterile (CMS) sugar beets were tested with regard to their potential for monitoring transgene now. As the pollen source, transgenic sugar beets were used that express recombinant DNA encoding viral (beet necrotic yellow vein virus) resistance, and antibiotic (kanamycin) and herbicide (glufosinate) tolerance genes. In a field trial, the effectiveness of a hemp (Cannabis sativa) stripe containment strategy was tested by measuring the frequency of pollinated CMS bait plants placed at different distances and directions from a transgenic pollen source. The results demonstrated the ineffectiveness of the containment strategy. Physiological and molecular tests confirmed the escape and production of transgenic offspring more than 200 m behind the hemp containment. Since absolute containment is unlikely to be effective, the CMS-bait plant detection system is a useful tool for other monitoring: purposes.

Saji, H., N. Nakajima, et al. (2005). "Monitoring the escape of transgenic oilseed rape around Japanese ports and roadsides." Environ Biosafety Res 4(4): 217-222.

An investigation was carried out to monitor the escape and spread of oilseed rape (Brassica napus) transgenic plants and the introgression of transgenes to its closely related feral species in Japan. We screened a total of about 7500 feral B. napus, 300 B. rapa, and 5800 B. juncea seedlings from maternal plants in 143 locations at several ports, roadsides, and riverbanks. The presence of glufosinate-resistance or glyphosate-resistance transgenes in these seedlings was confirmed by means of herbicide treatments and also immunochemical and DNA analyses. B. napus plants with herbicide-resistant transgenic seeds were found at five of six major ports and along two of four sampled roadsides in the Kanto District. Transgenic oilseed rape plants have not been commercially cultivated in Japan, suggesting that the transgenes would probably have come from imported transgenic seeds that were spilled during transportation to oilseed processing facilities. No transgenes were detected in seeds collected from B. napus plants growing along riverbanks in the Kanto District or in seeds from closely related species (B. rapa and B. juncea). To our knowledge, this is the first published example of feral, transgenic populations occurring in a nation where the transgenic crop has not been cultivated commercially.

Saltelli, A. and S. Funtowicz (2004). "The Precautionary Principle: implications for risk management strategies." Int J Occup Med Environ Health 17(1): 47-57.

The European Commission has published a Communication on the Precautionary Principle and a White Book on Governance. These provide us (as research civil servants of the Commission) an institutional framework for handling scientific information that is often incomplete, uncertain, and contested. But, although the Precautionary Principle is intuitively straightforward to understand, there is no agreed way of applying it to real decision-making. To meet this perceived need, researchers have proposed a vast number of taxonomies. These include ignorance auditing, type one-two-three errors, a combination of uncertainty and decision stakes through post-normal science and the plotting of ignorance of probabilities against ignorance of consequences. Any of these could be used to define a precautionary principle region inside a multidimensional space and to position an issue within that region. The role of anticipatory research is clearly critical but scientific input is only part of the picture. It is difficult to imagine an issue where the application of the Precautionary Principle would be non-contentious. From genetically-modified food to electro-smog, from climate change to hormone growth in meat, it is clear that: 1) risk and cost-benefit are only part of the picture; 2) there are ethical issues involved; 3) there is a plurality of interests and perspectives that are often in conflict; 4) there will be losers and winners whatever decision is made. Operationalization of the Precautionary Principle must preserve transparency. Only in this way will the incommensurable costs and benefits associated with different stakeholders be registered. A typical decision will include the following sorts of considerations: 1) the commercial interests of companies and the communities that depend on them; 2) the worldviews of those who might want a greener, less consumerist society and/or who believe in the sanctity of human or animal life; 3) potential benefits such as enabling the world's poor to improve farming; 4) risks such as pollution, gene-flow, or the effects of climate change. In this paper we will discuss the use of a combination of methods on which we have worked and that we consider useful to frame the debate and facilitate the dialogue among stakeholders on where and how to apply the Precautionary Principle.

Sanvido, O., J. Romeis, et al. (2007). Ecological impacts of genetically modified crops: Ten years of field research and commercial cultivation. Green Gene Technology: Research in an Area of Social Conflict. 107: 235-278.

The worldwide commercial cultivation of genetically modified (GM) crops has raised concerns about potential adverse effects on the environment resulting from the use of these crops. Consequently, the risks of GM crops for the environment, and especially for biodiversity, have been extensively assessed before and during their commercial cultivation. Substantial scientific data on the environmental effects of the currently commercialized GM crops are available today. We have reviewed this scientific knowledge derived from the past 10 years of worldwide experimental field research and commercial cultivation. The review focuses on the currently commercially available GM crops that could be relevant for agriculture in Western and Central Europe (i.e., maize, oilseed rape, and soybean), and on the two main GM traits that are currently commercialized, herbicide tolerance (HT) and insect resistance (IR). The sources of information included peer-reviewed scientific journals, scientific books, reports from regions with extensive GM crop cultivation, as well as reports from international governmental organizations. The data available so far provide no scientific evidence that the cultivation of the presently commercialized GM crops has caused environmental harm. Nevertheless, a number of issues related to the interpretation of scientific data on effects of GM crops on the environment are debated controversially. The present review highlights these scientific debates and discusses the effects of GM crop cultivation on the environment considering the impacts caused by cultivation practices of modern agricultural systems.

Sanvido, O., M. Stark, et al. (2006). Ecological impacts of genetically modified crops: Experiences from ten years of experimental field research and commercial cultivation, Agroscope Reckenholz-Tanikon, Swiss Confederation: 86.

Savadori, L., S. Savio, et al. (2004). "Expert and public perception of risk from biotechnology." Risk Anal 24(5): 1289-1299.

Risk perceptions of a series of biotechnology applications were examined in a public (nonexpert) sample and an expert sample. Compared with the experts, the public perceived all biotechnology applications as more risky. Both groups perceived food-related applications to be riskier than medical applications. Compared with the public, experts perceived both food and medical applications as less harmful and more useful. Experts also judged the risks posed from medical biotechnology applications as more familiar and acknowledged by people and science. Lay estimates of the risk of food applications were predicted by potential harm, potential benefits, science knowledge, and familiarity; experts' estimates were predicted only by harm and benefits. Lay estimates of the risk of medical applications were predicted by potential harm; experts' estimates were predicted by potential benefits, number and type of people exposed, and science knowledge. We discuss the implications of the results for risk communication about and management of different types of biotechnologies.

Saxena, D., C. N. Stewart, et al. (2004). "Larvicidal Cry proteins from Bacillus thuringiensis are released in root exudates of transgenic B. thuringiensis corn, potato, and rice but not of B. thuringiensis canola, cotton, and tobacco." Plant Physiol Biochem 42(5): 383-387.

Larvicidal proteins encoded by cry genes from Bacillus thuringiensis were released in root exudates from transgenic B. thuringiensis corn, rice, and potato but not from B. thuringiensis canola, cotton, and tobacco. Nonsterile soil and sterile hydroponic solution in which B. thuringiensis corn, rice, or potato had been grown were immunologically positive for the presence of the Cry proteins; from B. thuringiensis corn and rice, the soil and solution were toxic to the larva of the tobacco hornworm (Manduca sexta), and from potato, to the larva of the Colorado potato beetle (Leptinotarsa decemlineata), representative lepidoptera and coleoptera, respectively. No toxin was detected immunologically or by larvicidal assay in soil or hydroponic solution in which B. thuringiensis canola, cotton, or tobacco, as well as all near-isogenic non-B. thuringiensis plant counterparts or no plants, had been grown. All plant species had the cauliflower mosaic virus (CaMV) 35S promoter, except rice, which had the ubiquitin promoter from maize. The reasons for the differences between species in the exudation from roots of the toxins are not known. The released toxins persisted in soil as the result of their binding on surface-active particles (e.g. clay minerals, humic substances), which reduced their biodegradation. The release of the toxins in root exudates could enhance the control of target insect pests, constitute a hazard to nontarget organisms, and/or increase the selection of toxin-resistant target insects.

Saxena, D. and G. Stotzky (2000). "Insecticidal toxin from Bacillus thuringiensis is released from roots of transgenic Bt corn in vitro and in situ." FEMS Microbiol Ecol 33(1): 35-39.

The insecticidal toxin encoded by the cry1Ab gene from Bacillus thuringiensis was released in root exudates from transgenic Bt corn during 40 days of growth in soil amended to 0, 3, 6, 9, or 12% (v/v) with montmorillonite or kaolinite in a plant growth room and from plants grown to maturity in the field. The presence of the toxin in rhizosphere soil was determined by immunological and larvicidal assays. No toxin was detected in any soils from isogenic non-Bt corn or without plants. Persistence of the toxin was apparently the result of its binding on surface-active particles in the soils, which reduced the biodegradation of the toxin. The release of the toxin could enhance the control of insect pests or constitute a hazard to nontarget organisms, including the microbiota of soil, and increase the selection of toxin-resistant target insects.

Saxena, D. and G. Stotzky (2001). "Bt toxin uptake from soil by plants." Nat Biotechnol 19(3): 199.

Sayre, P. and R. J. Seidler (2005). "Application of GMOs in the US: EPA research & regulatory considerations related to soil systems." Plant and Soil 275(1-2): 77-91.

During the last 20 years recombinant biotechnology has resulted in the development of organisms with unique genetic compositions, some of which are for intentional release to the environment. While concerns have been raised that such organisms may be capable of inducing transient unintended environmental effects, longer-term perturbations to soil processes and non-target species effects have yet to be demonstrated. In parallel with the growth of the commercial biotechnology industry has come a significant growth in regulatory review processes intended to evaluate the risks of these GMO products. Under the Toxic Substances Control Act (TSCA), certain new microbial products that undergo pre-manufacture review are examined for human and environmental risks using data and other information received in accordance with the U.S. Environmental Protection Agency's (EPA's) "Points to Consider" guidance document. In the risk assessment process, carried out under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and the Federal Food, Drug and Cosmetic Act (FFDCA) authorities, EPA evaluates both microbial pesticide products and plants with pesticidal properties to determine if Federal safety standards are met. For all pesticide products, including genetically engineered pesticides, EPA receives testing of product composition and chemical properties, human health effects, environmental effects on non-target pests, and the fate of the pesticide in the environment. The EPA's Office of Research and Development supports risk assessment research related to such GMO products. This paper focuses on relevant EPA research and regulatory examples related to soil effects considerations for GMOs.

Scheffler, J. A., R. Parkinson, et al. (1995). "Evaluating the Effectiveness of Isolation Distances for Field Plots of Oilseed Rape (Brassica-Napus) Using a Herbicide- Resistance Transgene as a Selectable Marker." Plant Breeding 114(4): 317-321.

The effectiveness of 200- and 400-m isolation distances were evaluated for small-scale trials of oilseed rape (Brassica napus L.). These distances have been used for previous transgenic release experiments and are commonly adopted for production of basic and certified breeders seed. A 400-m(2) donor plot contained plants with a dominant transgene conferring resistance to the herbicide glufosinate-ammonium. This character was used as a selectable marker to measure the frequency of hybrid formation in 400-m(2) target plots of non- transgenic rape. Seeds produced by the non-transgenic plants were permitted to fall onto the plots and allowed to germinate. At the first true-leaf stage, the plants ware sprayed with glufosinate-ammonium. Surviving plants were resprayed, and a subsample assayed for the presence of the transgene using a colorimetric assay and Southern-blot analysis. The average frequency of hybridization over two replicates was 0.0156% at 200 m and 0.0038% at 400 m. These estimates are within the limits established for the production of basic seed (0.1%). Results indicated that bees were the most likely agent for long-distance pollen dispersal.

Schiemann, J. (2006). "Session VII: Risk management and monitoring." Environ Biosafety Res 5(4): 201-203.

Biosafety regulatory frameworks are intended to serve as mechanisms for ensuring the safe use of biotechnology products without imposing unacceptable risk to human health or the environment, or unintended constraints to technology transfer. In several regulatory systems GMO risk assessment has been separated from GMO risk management. As a consequence, risk assessment can be performed on a purely scientific basis, whereas risk management can take additional aspects (e.g. socio-economic or ethical) into consideration. For instance, the European Food Safety Authority (EFSA), the keystone of European Union risk assessment regarding food and feed safety, provides independent scientific advice and clear communication on existing and emerging risks in close collaboration with national authorities and in open consultation with its stakeholders. Risk management measures are not within the remit of EFSA, and remain the responsibility of the European Commission and Member States.

Schmidt, C. W. (2005). "Genetically modified foods: breeding uncertainty." Environ Health Perspect 113(8): A526-533.

Schmidt, M. and G. Bothma (2006). "Risk Assessment for Transgenic Sorghum in Africa: Crop-to-Crop Gene Flow in Sorghum bicolor (L.) Moench." Crop Sci 46(2): 790-798.

A crop-to-crop gene flow risk assessment study was conducted with Sorghum bicolor subsp. bicolor to estimate the impact of transgenic sorghum in (South) Africa. The trial was conducted with a central sorghum field (30 x 30 m) with male fertile donor plants that was surrounded by eight arms planted with male sterile recipient plants at a distance of 13 to 158 m from the central field. Gene flow was relatively high within the first 40 m and relatively low beyond that distance, but gene flow was detected even at the greatest distance investigated (158 m). The average hybridization or outcrossing rate for male sterile plants was 2.54% at 13 m, below 1% at a distance of 26 m or greater, and eventually dropping to 0.06% at 158 m. Outcrossing rates are expected to be even lower for male fertile plants, which were not investigated in this study. Mathematical models were used to estimate the maximum gene flow distance that is expected to be between approximately 200 and 700 m. These values are in line with observational data from sorghum plant breeders, who use an isolation distance of 100 m to achieve less than 1% genetic pollution. On the basis of the presence of fully fertile crop wild relatives and the weedy relative johnsongrass [S. halepense (L.) Pers.], which may form hybrids with crop sorghum, and on the fact that gene flow takes place, there is strong evidence that introgression of genetically modified- (GM)-sorghum into crops and crop wild relatives will take place once GM-sorghum is deployed.

Sears, M. K., R. L. Hellmich, et al. (2001). "Impact of Bt corn pollen on monarch butterfly populations: a risk assessment." Proc Natl Acad Sci U S A 98(21): 11937-11942.

A collaborative research effort by scientists in several states and in Canada has produced information to develop a formal risk assessment of the impact of Bt corn on monarch butterfly (Danaus plexippus) populations. Information was sought on the acute toxic effects of Bt corn pollen and the degree to which monarch larvae would be exposed to toxic amounts of Bt pollen on its host plant, the common milkweed, Asclepias syriaca, found in and around cornfields. Expression of Cry proteins, the active toxicant found in Bt corn tissues, differed among hybrids, and especially so in the concentrations found in pollen of different events. In most commercial hybrids, Bt expression in pollen is low, and laboratory and field studies show no acute toxic effects at any pollen density that would be encountered in the field. Other factors mitigating exposure of larvae include the variable and limited overlap between pollen shed and larval activity periods, the fact that only a portion of the monarch population utilizes milkweed stands in and near cornfields, and the current adoption rate of Bt corn at 19% of North American corn-growing areas. This 2-year study suggests that the impact of Bt corn pollen from current commercial hybrids on monarch butterfly populations is negligible.

Seralini, G. E., D. Cellier, et al. (2007). "New analysis of a rat feeding study with a genetically modified maize reveals signs of hepatorenal toxicity." Arch Environ Contam Toxicol 52(4): 596-602.

Health risk assessment of genetically modified organisms (GMOs) cultivated for food or feed is under debate throughout the world, and very little data have been published on mid- or long-term toxicological studies with mammals. One of these studies performed under the responsibility of Monsanto Company with a transgenic corn MON863 has been subjected to questions from regulatory reviewers in Europe, where it was finally approved in 2005. This necessitated a new assessment of kidney pathological findings, and the results remained controversial. An Appeal Court action in Germany (Munster) allowed public access in June 2005 to all the crude data from this 90-day rat-feeding study. We independently re-analyzed these data. Appropriate statistics were added, such as a multivariate analysis of the growth curves, and for biochemical parameters comparisons between GMO-treated rats and the controls fed with an equivalent normal diet, and separately with six reference diets with different compositions. We observed that after the consumption of MON863, rats showed slight but dose-related significant variations in growth for both sexes, resulting in 3.3% decrease in weight for males and 3.7% increase for females. Chemistry measurements reveal signs of hepatorenal toxicity, marked also by differential sensitivities in males and females. Triglycerides increased by 24-40% in females (either at week 14, dose 11% or at week 5, dose 33%, respectively); urine phosphorus and sodium excretions diminished in males by 31-35% (week 14, dose 33%) for the most important results significantly linked to the treatment in comparison to seven diets tested. Longer experiments are essential in order to indicate the real nature and extent of the possible pathology; with the present data it cannot be concluded that GM corn MON863 is a safe product.

Serratos-Hernandez, J. A., F. Islas-Gutierrez, et al. (2004). "Gene flow scenarios with transgenic maize in Mexico." Environ Biosafety Res 3(3): 149-157.

Maize diversity is widespread in Mexico and it has been stewarded by campesinos in small communities until the present. With the arrival of transgenic maize, the objective of this study is to analyze possible scenarios that could result if genetically modified maize were not regulated and openly available in Mexico. By applying a simple logistic model based on the conditions of maize production in Mexico, the dispersion of transgenic maize in different situations within fields of farmers is described. In traditional open systems of freely exchanged seed within communities it is concluded that the most likely outcome of GM maize release is the incorporation of transgenes in the genome of Mexican germplasm and possibly in that of teosinte.

Shaw, J. F., H. H. Chen, et al. (2002). "Extended flower longevity of Petunia hybrida plants transformed with boers, a mutated ERS gene of Brassica oleracea." Molecular Breeding 9(3): 211-216.

Petunia x hybrida Hort.Vilm.-Andr. was transformed with boers, a mutated allele of BOERS, an ethylene receptor sensor gene of Brassica oleracea. boers was obtained by removing an EcoRI cutting site with a silent mutation at Gly-521 and introducing a point mutation at Ile-62, replacing isoleucine with phenylalanine. Transformation was Agrobacterium tumefaciens mediated. Hygromycin resistant regenerants were tentatively confirmed as transformants by PCR's for HPH and boers and more definitively by Southern hybridization of genomic DNA with pBOERS4421. Flowers of transgenic plants retained turgidity and pigmentation considerably longer than those of untransformed controls, whether left undisturbed on plants or excised and placed in water. Furthermore, flowers were unaffected by exposure to exogenous ethylene. Excised shoots of transgenic plants released considerably more ethylene than those of untransformed plants. Transformed plants also produced apparently larger flowers. Unexpectedly higher mortality was observed, suggesting that the ethylene insensitive petunia plants were also lower in disease resistance.

Shaw, M. W., T. D. Harwood, et al. (2006). "Assembling spatially explicit landscape models of pollen and spore dispersal by wind for risk assessment." Proc Biol Sci 273(1594): 1705-1713.

Models of windblown pollen or spore movement are required to predict gene flow from genetically modified (GM) crops and the spread of fungal diseases. We suggest a simple form for a function describing the distance moved by a pollen grain or fungal spore, for use in generic models of dispersal. The function has power-law behaviour over sub-continental distances. We show that air-borne dispersal of rapeseed pollen in two experiments was inconsistent with an exponential model, but was fitted by power-law models, implying a large contribution from distant fields to the catches observed. After allowance for this 'background' by applying Fourier transforms to deconvolve the mixture of distant and local sources, the data were best fit by power-laws with exponents between 1.5 and 2. We also demonstrate that for a simple model of area sources, the median dispersal distance is a function of field radius and that measurement from the source edge can be misleading. Using an inverse-square dispersal distribution deduced from the experimental data and the distribution of rapeseed fields deduced by remote sensing, we successfully predict observed rapeseed pollen density in the city centres of Derby and Leicester (UK).

Shelton, A. M. (2003). "Considerations for conducting research in agricultural biotechnology." Journal of Invertebrate Pathology 83: 110-112.

Science has shown its increased vulnerability because of two recent high-profile articles published in major journals on corn produced through biotechnology: a laboratory report suggesting profound consequences to monarch butterfly populations due to Bt corn pollen and a report suggesting transgenic introgression into Mexican maize. While both studies have been widely regarded as having flawed methodology, publishing these studies has created great consternation in the scientific community, regulatory agencies and the general public. There are roles and responsibilities of scientists, scientific journals, the public media, public agencies, and those who oppose or advocate a specific technology, and serious consequences when those roles and responsibilities go awry. Modern communication may exacerbate the flow of misinformation and easily lead to a decline in public confidence about biotechnology and science. However, common sense tells us that scientific inquiry and the publication and reporting of results should be performed with high standards of ethical behavior, regardless of one's personal perspective on agricultural biotechnology.

Shelton, A. M. (2007). "Considerations on the use of transgenic crops for insect control." Journal of Development Studies 43(5): 890-900.

The adoption of agricultural technologies, whether developed through biotechnology or other methods, depends on social, political, regulatory and biological parameters. This article first presents an example of a low-input, non-biotechnological method of pest control that, while seemingly reasonable to researchers and extension agents, was not adopted by farmers. It then analyses a method for insect management developed through biotechnology that is becoming widely adopted. transgenic plants expressing insecticidal proteins from the bacterium Bacillus thuringiensis (Bt). Globally increasing adoption of Bt plants, by small and large farmers in both low- and high- income countries requires explanation in terms of biological properties of cropping systems and insect populations, alternative control techniques and social policy considerations.

Shelton, A. M. and M. K. Sears (2002). "The monarch butterfly controversy: scientific interpretations of a phenomenon (vol 27, pg 483, 2001)." Plant Journal 29(5): 679-679.

Shelton, A. M., J. Z. Zhao, et al. (2002). "Economic, ecological, food safety, and social consequences of the deployment of Bt transgenic plants." Annual Review of Entomology: 845-881.

Shen, B. C., C. N. Stewart, Jr., et al. (2006). "Correlated expression of gfp and Bt cry1Ac gene facilitates quantification of transgenic hybridization between Brassicas." Plant Biol (Stuttg) 8(5): 723-730.

Gene flow from transgenic oilseed rape (BRASSICA NAPUS) might not be avoidable, thus, it is important to detect and quantify hybridization events with its relatives in real time. Data are presented showing the correlation between genetically linked green fluorescent protein (GFP) with BACILLUS THURINGIENSIS (Bt) CRY1AC gene expression in hybrids formed between transgenic B. NAPUS "Westar" and a wild Chinese accession of wild mustard (B. JUNCEA) and hybridization between transgenic B. NAPUS and a conspecific Chinese landrace oilseed rape. Hybrids were obtained either by spontaneous hybridization in the field or by hand-crossing in a greenhouse. In all cases, transgenic hybrids were selected by GFP fluorescence among seedlings originating from seeds harvested from B. JUNCEA and the Chinese oilseed rape plants. Transgenicity was confirmed by PCR detection of transgenes. GFP fluorescence was easily and rapidly detected in the hybrids under greenhouse and field conditions. Results showed that both GFP fluorescence and Bt protein synthesis decreased as either plant or leaf aged, and GFP fluorescence intensity was closely correlated with Bt protein concentration during the entire vegetative lifetime in hybrids. These findings allow the use of GFP fluorescence as an accurate tool to detect gene-flow in time in the field and to conveniently estimate BT CRY1AC expression in hybrids on-the-plant.

Shrader-Frechette, K. S. (1998). "What risk management teaches us about ecosystem management." Landscape and Urban Planning 40: 141-150.

This paper outlines two of the dominant ecosystem-management paradigms, one based on the traditional paradigm of ecological risk assessment and the other based on the health paradigm of ecological risk assessment. After showing the central ethical strengths and weaknesses of the traditional paradigm and the health paradigm, the essay argues that the uncertainties surrounding these two paradigms require ecosystem management to focus on default assumptions. The argument is that, just as most of the major battles of risk management are being fought on the ground of stakeholder participation and default assumptions, so most of the important battles of ecosystem management need to be fought on the battleground of stakeholder participation and default assumptions. Otherwise massive scientific uncertainties will compromise the credibility of both ecology and environmental management. Coping with problems from dioxin to nuclear power, the contemporary risk-management community is witnessing a dramatic battle between ‘environmental hypochondriacs’ and ‘industrial cannibals’ wShrader-Frechette, K., 1994. Risk and ethics. In: Lindell, B. Ed.., Comprehending Radiation Risks. Swedish Risk Academy, Stockholm, pp. 167–182x. The environmental hypochondriacs often argue that only zero risk is ethically and environmentally acceptable. They forget that virtually nothing has zero risk, provided analysis can detect the smallest threats. The industrial cannibals frequently maintain that almost any level of risk is justifiable, provided that the economic benefits are substantial enough. They forget that not everything has a price. In more sophisticated and realistic risk-management circles, a similar battle pits the wholists against the reductionists. The wholists believe that risk is a multiattribute concept. For them, health and environmental risks are complex and extra-scientific, involving not only threats to human and planetary safety but also threats to values—to trust, autonomy, sustainability, cultural integrity, equal protection, due process, future generations, and free informed consent wSlovic, P., Flynn, J., Layman, M., 1991. Perceived risk, trust, and the politics of nuclear waste. Science, 254, pp. 1604–1605; Shrader-Frechette, K., 1991. Risk and Rationality. Univ. of California Press, Berkeleyx. The wholists believe that we manage health and environmental risks by reducing them and by enlisting the active participation of stakeholders in risk management. The reductionists, following part of the classic National Research CouncilrNational Academy of Sciences ‘Redbook’ account of risk, maintain that risk is a scientific concept. For them, health and environmental risks must be assessed scientifically, typically as an average annual probability of fatality wNational Research Council, 1983. Risk Assessment in the Federal Government: Managing the Process. National Academy Press, Washington, DCx. Following this definition, many reductionists believe that we handle health and environmental risks by educating members of the public—who supposedly are irrational, scientifically ignorant, and paranoid wWeinberg, A., 1988. Risk assessment, regulation, and the limits. In: Woodhead, A., Bender, M., Leonard, R.

Silbergeld, E. K. (1993). "Risk assessment: the perspective and experience of U.S. environmentalists." Environ Health Perspect 101(2): 100-104.

Risk assessment is a set of decision rules widely used in the United States for identifying and quantifying the risks of chemicals and other events for adverse effects to human health, usually cancer. Scientific criticism has been directed toward the default assumptions and test methods used in risk assessment by regulatory agencies. This paper evaluates the contribution of risk assessment as an instrument of public policy toward the timely and efficient resolution of controversial issues in environmental and occupational health. Experience with risk assessment during the past decade does not support its utility in this regard. Alternatives to risk assessment in its current formulation are discussed.

Simmons, G. A., L. Alphey, et al. (2007). Potenial use of a conditional lethal transgenic pink bollworm Pectinophora gossypiella in area-wide eradication or suppression programmes. Area-Wide Control of Insect Pests from Research to Field Implementation.

Singh, O. V., S. Ghai, et al. (2006). "Genetically modified crops: success, safety assessment, and public concern." Appl Microbiol Biotechnol 71(5): 598-607.

With the emergence of transgenic technologies, new ways to improve the agronomic performance of crops for food, feed, and processing applications have been devised. In addition, ability to express foreign genes using transgenic technologies has opened up options for producing large quantities of commercially important industrial or pharmaceutical products in plants. Despite this high adoption rate and future promises, there is a multitude of concerns about the impact of genetically modified (GM) crops on the environment. Potential contamination of the environment and food chains has prompted detailed consideration of how such crops and the molecules that they produce can be effectively isolated and contained. One of the reasonable steps after creating a transgenic plant is to evaluate its potential benefits and risks to the environment and these should be compared to those generated by traditional agricultural practices. The precautionary approach in risk management of GM plants may make it necessary to monitor significant wild and weed populations that might be affected by transgene escape. Effective risk assessment and monitoring mechanisms are the basic prerequisites of any legal framework to adequately address the risks and watch out for new risks. Several agencies in different countries monitor the release of GM organisms or frame guidelines for the appropriate application of recombinant organisms in agro-industries so as to assure the safe use of recombinant organisms and to achieve sound overall development. We feel that it is important to establish an internationally harmonized framework for the safe handling of recombinant DNA organisms within a few years.

Sisterson, M. S., Y. Carriere, et al. (2007). "Nontarget effects of transgenic insecticidal crops: implications of source-sink population dynamics." Environ Entomol 36(1): 121-127.

Widespread planting of transgenic insecticidal (TI) crops for pest control has raised concerns about potential harm to nontarget arthropods. Because the first generation of TI crops produce single Bacillus thuringiensis (Bt) toxins causing little or no harm to most nontarget arthropods, they are not likely to cause such negative effects. However, varieties of transgenic crops with multiple Bt toxins or novel toxins might be more harmful to nontarget arthropods. Field studies assessing nontarget effects typically compare the relative abundance of nontarget arthropods in TI crop fields to non-TI crop fields. However, for nontarget arthropods that are killed by TI crops, such analyses may miss important effects. Results from simulations of a spatially explicit population dynamics model show that large-scale planting of TI crops could cause three types of negative effects on nontarget arthropods that suffer mortality caused by TI crops: (1) lower abundance in TI fields than non-TI fields with little or no effect on abundance in non-TI fields, (2) lower abundance in TI fields than non-TI fields and decreased abundance in non-TI fields, and (3) loss of the arthropod from TI and non-TI fields. Simulation results show that factors increasing the potential for negative effects of TI crops on nontarget arthropods in non-TI fields are low reproduction, high emigration, high adoption of TI crops, high mortality in TI fields, insecticide sprays, and rotation of TI and non-TI fields. The results suggest that risk assessment should consider the regional distribution of transgenic crops and the life history traits of nontarget arthropods to identify the most vulnerable regions and nontarget species.

Slavov, G. T., S. P. DiFazio, et al. (2004). Gene flow in forest trees: gene migration patterns and landscape modeling of transgene dispersal in hybrid poplar. Introgression from Genetically Modified Plants in Wild Relatives. H. C. M. den Nijs, D. Bartsch and J. Sweet. Wallingford, UK, CAB International: 89-106.

Smith, B. D. (2007). "Behavior. The ultimate ecosystem engineers." Science 315(5820): 1797-1798.

Smouse, P. E., J. J. Robledo-Arnuncio, et al. (2007). "Implications of natural propagule flow for containment of genetically modified forest trees." Tree Genetics & Genomes 3(2): 141-152.

Propagule flow in populations of virtually all organisms has importance for both the genetic cohesion of the species and for its interaction with natural selection. It's relevance for the deployment of genetically modified organisms (GMOs) is that propagules can be expected to move, under a wide range of circumstances, and will carry transgenic elements with them. Any consideration of the potential risks of deploying GMOs in the wild must include an assessment of how far and how fast introduced elements are transferred to surrounding conspecific (and sometimes congeneric) populations. In practice, we need estimates of the rates/distances of both pollen and seed movement. There are analytical methods to characterize seed (maternity), pollen (paternity), and established offspring (parent-pair) data, but spatial limitations restrict the area that one can study, and these approaches require modification for application to propagule flow in GMOs. We can apply indirect methods to estimate male gamete dispersal based on pollen pool analysis for single mothers, when some degree of precision can be sacrificed in return for compensating gains in the spatial coverage, but the loss of precision is problematic for GMO tracking. Special methods have been developed for GMO tracking, and we shall show how to assess spatial movement of both transgene-carrying seeds and pollen and will illustrate with an example from Brassica napus, a well-studied crop species.

Smyth, S., G. G. Khachatourians, et al. (2002). "Liabilities and economics of transgenic crops." Nat Biotechnol 20(6): 537-541.

Snow, A. A. (2002). "Moving beyond 'industry vs ecologists' stereotype." Nature 420(6912): 121-.

Snow, A. A. (2002). "Transgenic crops why gene flow matters." Nat Biotechnol 20(6): 542-.

Snow, A. A., B. Andersen, et al. (1999). "Costs of transgenic herbicide resistance introgressed from Brassica napus into weedy B-rapa." Molecular Ecology 8(4): 605-615.

Wild relatives of genetically engineered crops can acquire transgenic traits such as herbicide resistance via spontaneous crop-wild hybridization. In agricultural weeds, resistance to herbicides is often a beneficial trait, but little is known about possible costs that could affect the persistence of this trait when herbicides are not used. We tested for costs associated with transgenic resistance to glufosinate when introgressed into weedy Brassica rapa. Crosses were made between transgenic B. napus and wild B. rapa from Denmark. F-1 progeny were backcrossed to B. rapa and BC1 plants were selected for chromosome numbers similar to B. rapa. Further backcrossing resulted in a BC2 generation that was hemizygous for herbicide resistance. We quantified the reproductive success of 457 BC3 progeny representing six full-sib families raised in growth rooms (plants were pollinated by captive bumblebees). Pollen fertility and seed production of BC3 plants were as great as those of B. rapa raised in the same growth rooms. Segregation for herbicide resistance in BC3 plants was 1:1 overall, but the frequency of resistant progeny was lower than expected in one family and higher than expected in another. There were no significant differences between transgenic and nontransgenic plants in survival or the number of seeds per plant, indicating that costs associated with the transgene are probably negligible. Results from this growth- chamber study suggest that transgenic resistance to glufosinate is capable of introgressing into populations of B. rapa and persisting, even in the absence of selection due to herbicide application.

Snow, A. A., D. A. Andow, et al. (2005). "Genetically engineered organisms and the environment: current status and recommendations." Ecol Appl 15(2): 377-404.

Snow, A. A., P. Moran-Palma, et al. (1998). "Fecundity, phenology, and seed dormancy of F-1 wild-crop hybrids in sunflower (Helianthus annuus, Asteraceae)." American Journal of Botany 85(6): 794-801.

Crop-to-wild hybridization has the potential to introduce beneficial traits into wild populations. Gene flow from genetically engineered crops, in particular, can transfer genes coding for traits such as resistance to herbicides, insect herbivores, disease, and environmental stress into wild plants. Cultivated sunflower (Helianthus annuus) hybridizes spontaneously with wild/weedy populations (also H. annuus), but little is known about the relative fitness of F-1 hybrids. In order to assess the ease with which crop-to-wild introgression can proceed, we compared characteristics of F-1 wild-crop progeny with those of purely wild genotypes. Two nontransgenic, cultivated varieties were crossed with wild plants from three different regions-Texas, Kansas, and North Dakota. Seed burial experiments in the region of origin showed that wild-crop seeds had somewhat higher germination rates (less dormancy) than wild seeds from Kansas and North Dakota, while no differences were seen in seeds from Texas. Progeny from each type of cross were grown in outdoor pots in Ohio and in a weedy field in Kansas to quantify lifetime fecundity and flowering phenology. Flowering periods of hybrid and wild progeny overlapped considerably, especially in plants from North Dakota and Texas, suggesting that these hybrids are very likely to backcross with wild plants. In general, hybrid plants had fewer branches, flower heads, and seeds than wild plants, but in two crosses the fecundity of hybrids was not significantly different from that of purely wild plants. In Ohio, wild-crop hybrids from North Dakota appeared to be resistant to a rust that infected 53 % of the purely wild progeny, indicating a possible benefit of "traditional" crop genes. In summary, our results suggest that F-1 wild-crop hybrids had lower fitness than wild genotypes, especially when grown under favorable conditions, but the F-1 barrier to the introgression of crop genes is quite permeable.

Snow, A. A., D. Pilson, et al. (2003). "A Bt transgene reduces herbivory and enhances fecundity in wild sunflowers." Ecological Applications 13(2): 279-286.

Gene flow from transgenic crops can introduce novel traits into related species, but the ecological importance of this process is unknown. Here, we report the first empirical evidence that wild plants can benefit from a bacterial transgene under uncaged, natural conditions. Cultivated sunflower (Helianthus annuus) is known to hybridize frequently with wild sunflower (H. annuus) in the western and midwestern United States. We studied a crop-developed Bacillus thuringiensis (Bt) transgene, cry1Ac, in backcrossed wild sunflower populations. Lepidopteran damage on transgenic plants was strongly reduced relative to control plants at our two study sites, while damage by several weevil and fly species was unaffected. Our results suggest that reduced herbivory caused transgenic plants to produce an average of 55% more seeds per plant relative to nontransgenic controls at the field site in Nebraska. A similar but nonsignificant trend was seen at the site in Colorado (14% more seeds per plant).. In a greenhouse experiment the transgene had no effect on fecundity, suggesting that it was not associated with a fitness cost. If Bt sunflowers are released commercially, we expect that Bt genes will spread to wild and weedy populations, limit damage from susceptible herbivores on these plants, and increase seed production when these herbivores are common.

Snow, A. A., K. L. Uthus, et al. (2001). "Fitness of hybrids between weedy and cultivated radish: Implications for weed evolution." Ecological Applications 11(3): 934-943.

Weed species are known to evolve rapidly with their associated crops. A better understanding of the mechanisms and rates of weed evolution could aid in limiting or at least anticipating this process. Spontaneous hybridization between crops and related weed species can transfer crop genes coding for fitness-enhancing traits to wild populations, but little is known about how easily this takes place in various weed-crop complexes. We studied interspecific hybrids between wild and cultivated radishes (Raphanus raphanistrum X R. sativus), which often co-occur and share pollinators. To determine whether the F, generation represents a strong barrier to subsequent introgression, we compared the fitness of wild plants and wild- crop hybrids. Two experiments were carried out in Michigan, USA, one with potted plants and the other involving four artificially established populations. In the artificial populations, we used white flower color, a dominant, crop- specific allele, to document the persistence of crop genes over time. Wild plants had yellow flowers, which is a recessive trait. F. hybrids had lower fitness than wild plants due to lower pollen fertility, fewer seeds per plant, and delayed flowering. Despite these disadvantages, hybrids contributed substantially,to each population's gene pool. After 3 yr, frequencies of white-flowered plants in the artificial populations ranged from 8% to 22%, demonstrating that crop genes persisted. Other studies of flower color variation in wild populations of R. raphanistrum provide circumstantial evidence for frequent crop-to-wild gene flow. We predict that, if cultivated radish is engineered to possess transgenes coding for traits such as resistance to insect herbivores, disease, herbicides, or environmental stress, these fitness-related crop genes will easily spread to R. raphanistrum.

Soboleva, T. K., P. R. Shorten, et al. (2003). "Qualitative theory of the spread of a new gene into a resident population." Ecological Modelling 163(1-2): 33-44.

This work addresses the problems that arise in the estimation of the risk of invader/unwanted GMO spread and the optimal release of desired genes into a population through the release of transgenic individuals. On the basis of a general model of the propagation of an advantageous allele through a population we analyze the thresholds and critical aggregations in gene frequency necessary for the spread of new gene carriers. It is shown that if the invader appears at one place in the ecosystem then it will not spread throughout the ecosystem unless it exceeds some critical threshold, where the critical threshold is defined in terms of both the amount and distribution of the invader. The value of the critical threshold will depend on the fitness of the invader relative to the fitness of the resident organisms in the ecosystem and the mechanism of its dispersion. It is also shown that typically an invader will not spread symmetrically, even if the environment is isotropic, but rather develops clusters that form filaments within the ecosystem. We also demonstrate that if the invader aggregation is sufficiently large then after an initial period the advance of the invader into the resident population takes the form of a traveling wave. The speed of this wave tends to a speed characteristic of the relative fitness and dispersive mechanisms of the invader. (C) 2002 Elsevier Science B.V. All rights reserved.

Soleri, D., D. A. Cleveland, et al. (2005). "Understanding the potential impact of transgenic crops in traditional agriculture: maize farmers' perspectives in Cuba, Guatemala and Mexico." Environ Biosafety Res 4(3): 141-166.

Genetically engineered transgenic crop varieties (TGVs) have spread rapidly in the last 10 years, increasingly to traditionally-based agricultural systems (TBAS) of the Third World both as seed and food. Proponents claim they are key to reducing hunger and negative environmental impacts of agriculture. Opponents claim they will have the opposite effect. The risk management process (RMP) is the primary way in which TGVs are regulated in the US (and many other industrial countries), and proponents claim that the findings of that process in the US and its regulatory consequences should be extended to TBAS. However, TBAS differ in important ways from industrial agriculture, so TGVs could have different effects in TBAS, and farmers there may evaluate risks and benefits differently. To evaluate some potential impacts of TGVs in TBAS we used the RMP as a framework for the case of Bt maize in Mesoamerica and Cuba. We interviewed 334 farmers in Cuba, Guatemala and Mexico about farming practices, evaluations of potential harm via hypothetical scenarios, and ranking of maize types. Results suggest high potential for transgene flow via seed, grain and pollen; differences in effects of this exposure in TBAS compared with industrial agriculture; farmers see some potential consequences as harmful. Perceptions of harm differ among farmers in ways determined by their farming systems, and are different from those commonly assumed in industrial systems. An RMP including participation of farmers and characteristics of TBAS critical for their functioning is necessary to ensure that investments in agricultural technologies will improve, not compromise these agricultural systems.

Soleri, D., D. A. Cleveland, et al. (2006). "Transgenic crops and crop varietal diversity: The case of maize in Mexico." Bioscience 56(6): 503-513.

Transgenic crop varieties are a rapidly expanding and controversial technology. Their effects on biological and cultural diversity are a key issue in an often polarized debate. Here we provide answers to questions about one important example, that of transgenic maize in Mexico. In situ maize diversity in Mexico is present in traditional varieties in farmers' fields, and in wild and weedy relatives of maize. It is likely that transgenes are present in farmers' local maize varieties, but it is unknown whether they have introgressed. Socioeconomic changes, including migration, trade liberalization, and reduced support for Mexican farmers, may also affect maize diversity. Diversity may increase, decrease, or remain the same, but whether this is viewed as good or bad will depend on subjective values.

Song, Z. P., B. R. Lu, et al. (2003). "Gene flow from cultivated rice to the wild species Oryza rufipogon under experimental field conditions." New Phytologist 157(3): 657-665.

Here, the gene flow from a cultivated rice variety (Minghui-63) to common wild rice (Oryza rufipogon) was investigated to assess the biosafety risk associated with the environmental release of transgenic varieties.Four experimental designs differing in the spatial arrangement of the Minghui-63 and O. rufipogon plants were used in experiments conducted in an isolated rice field in Hunan Province, southern China, where O. rufipogon occurs naturally.Natural hybridization events between the two species were detected by scoring a simple sequence repeat (SSR) molecular marker. A total of 296 hybrids were identified from 23 776 seedlings that were randomly germinated from > 80 000 seeds collected from O. rufipogon. The occurrence of the crop-to-wild gene flow was significantly associated with wind direction and frequencies of the gene flow, which decreased significantly with distance from the pollen sources. The maximum observed distance of gene flow was 43.2 m.The results indicated that gene flow from cultivated rice to O. rufipogon occurred at a considerable rate. Therefore, isolation measures should be considered when deploying transgenic rice in the sympatric regions of the wild rice, and when establishing in situ conservation of O. rufipogon. The experimental system in this study can be used for biosafety assessment of transgene escape of other wind-pollinated crops.

Soule, E. d. (2004). "The precautionary principle and the regulation of U.S. food and drug safety." J Med Philos 29(3): 333-350.

This article probes the advisability of regulating U.S. food and drug safety according to the precautionary principle. To do so, a precautionary regulatory regime is formulated on the basis of the beliefs that motivate most proponents of this initiative. That hypothetical regime is critically analyzed on the basis of an actual instantiation of a similarly stylized initiative. It will be argued that the precautionary principle entails regulatory constraints that are apt to violate basis tenets of political legitimacy. The modifications that would change this finding would also change precautionary regulation to the point that it would be indistinguishable from orthodox safety protocols. It is concluded on the basis of its impoverished content that the precautionary principle should not be taken seriously as a formal approach to the regulation of U.S. food and drug safety.

Spangenberg, G., N. Petrovska, et al. (2004). Low-pollen-allergen ryegrasses: towards a continent free of hay fever?: 121-128.

The ryegrasses (Lolium spp.) are the major grass species sown for forage and amenity use in temperate areas of the world. Pollen of ryegrass is a widespread source of airborne allergens and is a major cause of hay fever and seasonal allergic asthma, which affect approximately 25% of the population in cool temperate climates. The main allergens of ryegrass pollen are the proteins Lol p 1 (35 kDa) and Lol p 2 (11 kDa). Lol p 1 and Lol p 2 belong to two major classes of grass pollen allergens to which over 90% of pollen-allergic patients are sensitive. In spite of being conserved in many plant species, the functional in planta role of these pollen allergen proteins remains largely unknown. We have generated and analysed transgenic plants with reduced levels of the main pollen allergens, Lol p 1 and Lol p 2 in the most important worldwide cultivated ryegrass species, L. perenne (perennial ryegrass) and L. multiflorum (Italian ryegrass). These transgenic plants will allow the study of the functional in planta role of these pollen proteins and the determination of potential for development of hypo-allergenic ryegrass cultivars. The commercial release of cultivars of perennial ryegrass and Italian ryegrass with reduced pollen allergens offers the potential to reduce subsequently the incidence of seasonal allergic responses. The prospects of reducing the incidence of hay fever in Australia will be increased through the widespread use of low-allergen ryegrasses.

Spencer, L. J. and A. A. Snow (2001). "Fecundity of transgenic wild-crop hybrids of Cucurbita pepo (Cucurbitaceae): implications for crop-to-wild gene flow." Heredity 86: 694-702.

Hybridization between crops and their weedy or wild relatives is an area of concern because the widespread use of genetically engineered crops may allow novel, beneficial transgenes to enter nearby populations. We compared fitness components of wild Cucurbita pepo from Arkansas, USA, with wild-crop hybrids derived from yellow squash (a cultivar of C. pepo with transgenic resistance to two viruses). Wild and hybrid progeny were grown in agricultural fields in Arkansas (1996-98) and Ohio (1996) in six similar experiments. Cross types (wild and hybrid) did not differ significantly in seedling survival, which exceeded 85% in all cases. In Ohio, where more detailed observations were made, hybrid plants produced 41% as many mate flowers, 21% as many female flowers, and 28% as many seeds as wild plants. At all sites, flowering periods of the two cross types overlapped extensively. Putative virus symptoms were more common in wild plants than in hybrids. Lifetime fecundity varied considerably among sites and years. The average fecundity of hybrids ranged from 453 to 4497 seeds per plant and represented 15% - 53% of the numbers of seeds produced by wild plants in the same experiments. These results suggest that the F-1 generation does not represent a strong barrier to the introgression of neutral or beneficial crop genes into free- living populations of C. pepo.

Staniland, B. K., P. B. E. McVetty, et al. (2000). "Effectiveness of border areas in confining the spread of transgenic Brassica napus pollen." Canadian Journal of Plant Science 80(3): 521-526.

The development of transgenic Brassica napus L. cultivars requires field trials in agricultural settings. For field testing of transgenic constructs that have not been granted full environmental release, current Canadian Government regulations require either large isolation zones (200 m) or 10 m wide borders of synchronously flowering, non-transgenic B. Napus to contain transgenic pollen. To investigate the effectiveness of border areas in containing transgenic B. napus pollen, border areas 15 to 30 m wide were planted around 30 m x 60 m central plots of bromoxynil-herbicide-resistant transgenic B. napus strains. Four field trials were conducted at Carman and Winnipeg, Manitoba, Canada in 1994 and 1995. Seed samples were harvested from the border area at 0, 2.5, 5, 10, and 15 m for the four cardinal directions and additionally at 20, 25, and 30 m for two cardinal directions. These seed samples were planted in the field in 1995 and 1996 and the seedlings screened for the presence of bromoxynil-resistant plants (i.e., from outcrossed seeds). Distance from the central plot significantly affected outcrossing rates while environment (site-year) and direction effects were non-significant. Outcrossing rates averaged 0.70% at 0 m and declined exponentially to 0.02% at 30 m. More than four-fifths of the total outcross events detected occurred in the first 10 m of border area indicating that border areas effectively reduce pollen-mediated gene flow in B. napus but cannot completely eliminate it.

Stanley-Horn, D. E., G. P. Dively, et al. (2001). "Assessing the impact of Cry1Ab-expressing corn pollen on monarch butterfly larvae in field studies." Proc Natl Acad Sci U S A 98(21): 11931-11936.

Survival and growth of monarch larvae, Danaus plexippus (L.), after exposure to either Cry1Ab-expressing pollen from three Bacillus thuringiensis (Bt) corn (Zea mays L.) events differing in toxin expression or to the insecticide, lambda-cyhalothrin, were examined in field studies. First instars exposed to low doses ( approximately 22 grains per cm(2)) of event-176 pollen gained 18% less weight than those exposed to Bt11 or Mon810 pollen after a 5-day exposure period. Larvae exposed to 67 pollen grains per cm(2) on milkweed leaves from within an event-176 field exhibited 60% lower survivorship and 42% less weight gain compared with those exposed to leaves from outside the field. In contrast, Bt11 pollen had no effect on growth to adulthood or survival of first or third instars exposed for 5 days to approximately 55 and 97 pollen grains per cm(2), respectively. Similarly, no differences in larval survivorship were observed after a 4-day exposure period to leaves with 504-586 (within fields) or 18-22 (outside the field) pollen grains per cm(2) collected from Bt11 and non-Bt sweet-corn fields. However, survivorship and weight gain were drastically reduced in non-Bt fields treated with lambda-cyhalothrin. The effects of Bt11 and Mon810 pollen on the survivorship of larvae feeding 14 to 22 days on milkweeds in fields were negligible. Further studies should examine the lifetime and reproductive impact of Bt11 and Mon810 pollen on monarchs after long-term exposure to naturally deposited pollen.

Stewart, C. N., M. J. Adang, et al. (1996). "Insect control and dosage effects in transgenic canola containing a synthetic Bacillus thuringiensis crylAc gene." Plant Physiology 112(1): 115-120.

Zygotic hypocotyls of canola (Brassica napus L.) cv Oscar, cv Westar, and the breeding line UCA1 88-208 were transformed with a truncated synthetic Bacillus thuringiensis insecticidal crystal protein gene (Bt crylAc) under the control of the cauliflower mosaic virus 35S promoter using Agrobacterium tumefaciens-mediated transformation. Fifty-seven independently transformed lines were produced, containing 1 to 12 copies of the transgenes. A range of cry expressors was produced from 0 to 0.4% Cry as a percentage of total extractable protein. The Brassica specialists, the diamondback moth (Plutella xylostella L.) and the cabbage looper (Trichoplusia ni Hubner), were completely controlled by low-, medium-, and high-expressing lines. Whereas control of the generalist lepidopteran, the corn earworm (Helicoverpa tea Boddie), was nearly complete, the other generalist caterpillar tested, the beet armyworm (Spodoptera exigua Hubner), showed a dose response that had a negative association between defoliation and cry expression. These plants were produced as models for an ecological research assessment of the risk involved in the field release of naturalized transgenic plants harboring a gene (Bt) that confers higher relative fitness under herbivore-feeding pressure.

Stewart, C. N., Jr., M. D. Halfhill, et al. (2003). "Transgene introgression from genetically modified crops to their wild relatives." Nat Rev Genet 4(10): 806-817.

Transgenes engineered into annual crops could be unintentionally introduced into the genomes of their free-living wild relatives. The fear is that these transgenes might persist in the environment and have negative ecological consequences. Are some crops or transgenic traits of more concern than others? Are there natural genetic barriers to minimize gene escape? Can the genetic transformation process be exploited to produce new barriers to gene flow? Questions abound, but luckily so do answers.

Stewart, C. N., Jr., H. A. t. Richards, et al. (2000). "Transgenic plants and biosafety: science, misconceptions and public perceptions." Biotechniques 29(4): 832-836, 838-843.

One usually thinks of plant biology as a non-controversial topic, but the concerns raised over the biosafety of genetically modified (GM) plants have reached disproportionate levels relative to the actual risks. While the technology of changing the genome of plants has been gradually refined and increasingly implemented, the commercialization of GM crops has exploded. Today's commercialized transgenic plants have been produced using Agrobacterium tumefaciens-mediated transformation or gene gun-mediated transformation. Recently, incremental improvements of biotechnologies, such as the use of green fluorescent protein (GFP) as a selectable marker, have been developed. Non-transformation genetic modification technologies such as chimeraplasty will be increasingly used to more precisely modify germplasm. In spite of the increasing knowledge about genetic modification of plants, concerns over ecological and food biosafety have escalated beyond scientific rationality. While several risks associated with GM crops and foods have been identified, the popular press, spurred by colorful protest groups, has left the general public with a sense of imminent danger. Reviewed here are the risks that are currently under research. Ecological biosafety research has identified potential risks associated with certain crop/transgene combinations, such as intra- and interspecific transgene flow, persistence and the consequences of transgenes in unintended hosts. Resistance management strategies for insect resistance transgenes and non-target effects of these genes have also been studied. Food biosafety research has focused on transgenic product toxicity and allergenicity. However, an estimated 3.5 x 10(12) transgenic plants have been grown in the U.S. in the past 12 years, with over two trillion being grown in 1999 and 2000 alone. These large numbers and the absence of any negative reports of compromised biosafety indicate that genetic modification by biotechnology poses no immediate or significant risks and that resulting food products from GM crops are as safe as foods from conventional varieties. We are increasingly convinced that scientists have a duty to conduct objective research and to effectively communicate the results--especially those pertaining to the relative risks and potential benefits--to scientists first and then to the public. All stakeholders in the technology need more effective dialogues to better understand risks and benefits of adopting or not adopting agricultural biotechnologies.

Stewart, P. A. and W. McLean (2004). "Fear and hope over the third generation of agricultural biotechnology: analysis of public response in the Federal Register [electronic resource]." AgBioForum 7(3).

The third generation of agricultural biotechnology looms large as plant-made pharmaceuticals (PMPs) and plant-made industrial products (PMIPs) both promise new, cheaper, and more plentiful pharmaceutical drugs and industrial products, such as plastics, cosmetics, enzymes, and epoxies. At the same time, they threaten the US food supply through adventitious presence (e.g., inadvertent mixing) of PMPs/PMIPs with the traditional food supplya concern brought home by the StarLink and Prodigene controversies in the past few years. This paper explores the third generation of agricultural biotechnology by looking at the products being developed and field tested and the regulations being implemented to address environmental release of PMPs and PMIPs. We next address the overwhelming public response to Federal Register notices concerning field release of PMPs and PMIPs and consider both the unprecedented volume of responses and their content, which reveals public and industry debate in terms of how to define science, governmental trust, and emotional response to the new technologies. We conclude by considering implications for not only PMPs and PMIPs, but also agricultural biotechnology in general.

Stirling, A. and S. Mayer (2000). "Precautionary approaches to the appraisal of risk: a case study of a genetically modified crop." Int J Occup Environ Health 6(4): 296-311.

There are strong scientific reasons for holding the broader scope of precautionary approaches to be more consistent with the scientific foundations of rational choice and probability theory than are conventional narrow risk-assessment techniques. The imperatives both of science and precaution can be seen to pull in the same direction. The regulatory appraisal of risk should become more systematic and broader in scope. In particular, a set of criteria can be developed concerning the need for greater humility, completeness, transparency, and participation in regulatory appraisal, with specific attention to the comparison of different options (including mixtures of options), the consideration of benefits and justifications, and the systematic "mapping" of the ways in which different framing assumptions lead to different pictures of performance. A case study of a pilot exercise applying a multi-criteria mapping method to the regulatory appraisal of a genetically modified crop is reported. The results are more complete than orthodox risk assessment, in that they embody consideration of an unlimited array of issues and include consideration of a wide range of different strategic alternatives to the use of GM technologies. It is concluded that conventional regulatory appraisal might be adapted to better address the imperatives of both science and precaution.

Stotzky, G. (2004). "Persistence and biological activity in soil of the insecticidal proteins from Bacillus thuringiensis, especially from transgenic plants." Plant and Soil 266(1-2): 77-89.

Insecticidal proteins produced by various subspecies (kurstaki, tenebrionis, and israelensis) of Bacillus thuringiensis (Bt) bound rapidly and tightly on clays, both pure mined clay minerals and soil clays, on humic acids extracted from soil, and on complexes of clay and humic acids. Binding reduced susceptibility of the proteins to microbial degradation. However, bound proteins retained biological activity. Purified Cry1Ab protein and protein released from biomass of transgenic Bt corn and in root exudates of growing Bt corn (13 hybrids representing three transformation events) exhibited binding and persistence in soil. Insecticidal protein was also released in root exudates of Bt potato (Cry3A protein) and rice (Cry1Ab protein) but not in root exudates of Bt canola, cotton, and tobacco (Cry1Ac protein). Vertical movement of Cry1Ab protein, either purified or in root exudates or biomass of Bt corn, decreased as the concentration of the clay minerals, kaolinite or montmorillonite, in soil increased. Biomass of transgenic Bt corn decomposed less in soil than biomass of near-isogenic non-Bt corn, possibly because biomass of Bt corn had a significantly higher content of lignin than biomass of non-Bt corn. Biomass of Bt canola, cotton, potato, rice, and tobacco also decomposed less than biomass of the respective near-isogenic non-Bt plants. However, the lignin content of these Bt plants, which was significantly less than that of Bt corn, was not significantly different from that of their near-isogenic non-Bt counterparts, although it was consistently higher. The Cry1Ab protein had no consistent effects on organisms (earthworms, nematodes, protozoa, bacteria, fungi) in soil or in vitro. The Cry1Ab protein was not taken up from soil by non-Bt corn, carrot, radish, or turnip grown in soil in which Bt corn had been grown or into which biomass of Bt corn had been incorporated.

Strauss, S., W. Boerjan, et al. (1999). "Forest biotechnology makes its position known." Nat Biotechnol 17(12): 1145-.

Strauss, S. H. (2002). "Trees, homologs, and poisons." Science JT - Science (New York, N.Y.) 296(5566): 262-.

Strauss, S. H. (2003). "Genetic technologies. Genomics, genetic engineering, and domestication of crops." Science JT - Science (New York, N.Y.) 300(5616): 61-62.

Strauss, S. H. (2003). "Regulating biotechnology as though gene function mattered." Bioscience 53(5): 453-454.

In this issue of BioScience, Jim Hancock suggests a sensible way to improve the process of assigning risk, and thus implicitly to improve regulatory schemes, e.g. place the emphasis on the transgenic trait, the crop host, and the presence of wild relatives. He also proposes that large classes of transgenic crops, depending on their gene and biology, be exempted from requirements for most kinds of environmental studies.

Strauss, S. H. (2003). "Reply." Science 301: 167-167.

Strauss, S. H. (2004). "Forest biotechnology--thriving despite controversy." New Phytol 163: 9-11.

Strauss, S. H. and H. D. Bradshaw (2004). The bioengineered forest: challenges for science and society. Washington, D.C., Resources for the Future.

The book examines the significant technical and legal hurdles involved in genetic engineering, the undesirable environmental and social consequences that might result from its misapplication, and the risks for businesses that are looking too exclusively for near-term benefits. It contains papers presented at the symposium held during July 2001 at Skamania Lodge in Stevenson, Washington, USA. The book is divided into 2 parts. The first part (6 papers) deals with the broad context of forestry, the technological possibilities and the research needed to allow responsible use of genetically engineered plantation trees. The second part (7 papers) comprises discussion on the pitfalls, costs and diverse risks of impetuous, poorly planned or socially undesirable applications. The chapters of the book reveal the following key themes: communication challenges are substantial; trust and social control are key issues; legal obstacles are great; benefits are large and diverse; and risks are complex.

Strauss, S. H. and A. M. Brunner (2004). Tree biotechnology in the twenty-first century: transforming trees in the light of comparative genomics. The bioengineered forest: challenges for science and society. S. H. Strauss and H. D. Bradshaw: 76-97.

Tree breeding and the obstacles encountered are discussed, and how genetic engineering might solve some major problems inherent in tree domestication. The structural challenges from the scientific, social and business perspectives that stand in the way of technological process are presented.

Strauss, S. H., A. M. Brunner, et al. (2004). "Ten lessons from 15 years of transgenic Populus research." Forestry 77(5): 455-465.

Based on extensive experience with transgenic poplars in laboratory and field environments, we have found that transformation is an extremely useful tool for research in biotechnology and functional genomics. The key lessons from our experience are: (1) stable gene expression is the rule in vegetatively propagated transgenic poplars; (2) somaclonal variation is modest and manageable; (3) transformation and field tests are extraordinary functional genomics methods; (4) there are many social and technical motivations for transformation centres; (5) regulations may choke biotechnology without scientist involvement; (6) the value of transgenic traits look high, but await careful, broad evaluation; (7) public-sector scientists need to play a serious, free role in value studies; (8) gene flow is complex and needs careful consideration; (9) sterility systems can be developed via diverse means; and (10) domestication transgenes can provide new avenues to promote biosafety. In short, transformation in poplar is extremely reliable and there are diverse and promising means for improving biosafety, but considerable time, institutional commitments and public–private partnerships are required to deliver them to society.

Strauss, S. H., M. M. Campbell, et al. (2001). "Plantation certification & genetic engineering: FSC's ban on research is counterproductive." Journal of Forestry 99(12): 4-7.

This paper reviews the methods and goals of tree genetic engineering research, and argues that the Forest Stewardship Council's ban on research is counterproductive because certified companies cannot easily participate in the field research needed to assess the value and biosafety of genetically modified trees.

Strauss, S. H., P. Coventry, et al. (2001). "Certification of genetically modified forest plantations." International Forestry Review 3(2): 85-102.

Strauss, S. H., S. P. DiFazio, et al. (2001). "Genetically modified poplars in context." Forestry chronicle 77(2): 271-279.

Poplars (<i>Populus</i>) have emerged as a model organism for forest biotechnology, and genetic modification (GM: asexual gene transfer) is more advanced for this genus than for any other tree. The goal of this paper is to consider the benefits expected from the use of GM poplar trees, and the most significant claims made for environmental harm, by comparing them to impacts and uncertainties that are generally accepted as part of intensive tree culture. We focus on the four traits with greatest commercialization potential in the near term: wood modification, herbicide tolerance, insect resistance, and flowering control. After field trials and selection of the top performing trees, similar to that during conventional poplar breeding, GM poplars appear vigorous and express their new traits reliably. The ecological issues expected from use of GM poplars appear similar in scope to those managed routinely during conventional plantation culture, which includes the use of exotic and hybrid genotypes, short rotations, intensive weed control, fertilizer application, and density control. The single-gene traits under consideration for commercial use are unlikely to cause a significant expansion in ecological niche, and thus to substantially alter poplar's ability to "invade" wild populations. We conclude that the ecological risks posed by GM poplars are similar in magnitude, though not in detail, to those of routine poplar culture. We also argue that the tangible economic and environmental benefits of GM poplars for some uses warrant their near-term adoption - if coupled with adaptive research and monitoring - so that their economic and ecological benefits, and safety, can be studied on commercially and ecologically relevant scales. We believe that the growing demand for both wood products and ecological services of forests justifies vigorous efforts to increase wood production on land socially zoned for tree agriculture, plantations, or horticulture. This is the key reason for poplar biotechnology: the combination of economic efficiency with reduction of farm and forestry impact on the landscape.

Strauss, S. H., K. F. Raffa, et al. (2000). "Ethics and genetically engineered plantations." J Forestry 98(7).

Sundstrom, L. F., M. Lohmus, et al. (2007). "Gene-environment interactions influence ecological consequences of transgenic animals." Proc Natl Acad Sci U S A 104(10): 3889-3894.

Production of transgenic animals has raised concern regarding their potential ecological impact should they escape or be released to the natural environment. This concern has arisen mainly from research on laboratory-reared animals and theoretical modeling exercises. In this study, we used biocontained naturalized stream environments and conventional hatchery environments to show that differences in phenotype between transgenic and wild genotypes depend on rearing conditions and, critically, that such genotype-by-environment interactions may influence subsequent ecological effects in nature. Genetically wild and growth hormone transgenic coho salmon (Oncorhynchus kisutch) were reared from the fry stage under either standard hatchery conditions or under naturalized stream conditions. When reared under standard hatchery conditions, the transgenic fish grew almost three times longer than wild conspecifics and had (under simulated natural conditions) stronger predation effects on prey than wild genotypes (even after compensation for size differences). In contrast, when fish were reared under naturalized stream conditions, transgenic fish were only 20% longer than the wild fish, and the magnitude of difference in relative predation effects was much reduced. These data show that genotype-by-environment interactions can influence the relative phenotype of transgenic and wild-type organisms and that extrapolations of ecological consequences from phenotypes developed in the unnatural laboratory environment may lead to an overestimation or underestimation of ecological risk. Thus, for transgenic organisms that may not be released to nature, the establishment of a range of highly naturalized environments will be critical for acquiring reliable experimental data to be used in risk assessments.

Suzuki, D. (2006). "A little knowledge...let's not allow the dazzling promise of gene technologies to blind us to their dangers." New Sci 191(2570): 18.

Tabashnik, B. E., Y. Carriere, et al. (2003). "Insect resistance to transgenic Bt crops: Lessons from the laboratory and field." Journal of Economic Entomology 96(4): 1031-1038.

Transgenic crops that produce insecticidal toxins from the bacterium Bacillus thuringiensis (Bt) grew on >62 million ha worldwide from 1996 to 2002. Despite expectations that pests would rapidly evolve resistance to such Bt crops, increases in the frequency of resistance caused by exposure to Bt crops in the field have not yet been documented. in laboratory and greenhouse tests, however, at least seven resistant laboratory strains of three pests (Plutella xylostella [L.], Pectinophora gossypiella [Saunders], and Helicoverpa armigera [Hubner]) have completed development on Bt crops. In contrast, several other laboratory strains with 70- to 10,100-fold resistance to Bt toxins in diet did not survive on Bt crops. Monitoring of field populations in regions with high adoption of Bt crops has not yet detected increases in resistance frequency. Resistance monitoring examples include Ostrinia nubilalis (Hubner) in the United States (6 yr), P. gossypiella in Arizona (5 yr), H. armigera in northern China (3 yr), and Helicoverpa zea (Boddie) in North Carolina (2 yr). Key factors delaying resistance to Bt crops are probably refuges of non-Bt host plants that enable survival of susceptible pests, low initial resistance allele frequencies, recessive inheritance of resistance to Bt crops, costs associated with resistance that reduce fitness of resistant individuals relative to susceptible individuals on non-Bt hosts ("fitness costs"), and disadvantages suffered by resistant strains on Bt hosts relative to their performance on non-Bt hosts ("incomplete resistance"). The relative importance of these factors varies among pest-Bt crop systems, and violations of key assumptions of the refuge strategy (low resistance allele frequency and recessive inheritance) may occur in some cases. The success of Bt crops exceeds expectations of many, but does not preclude resistance problems in the future.

Tabei, Y., K. Oosawa, et al. (1994). "Environmental Risk-Evaluation of the Transgenic Melon with Coat Protein Gene of Cucumber Mosaic-Virus in a Closed and a Semiclosed Greenhouses .1." Breeding Science 44(1): 101-105.

Environmental risk evaluation of transgenic melon plants introduced with coat protein gene of cucumber mosaic virus was carried out in a closed and a semiclosed greenhouse. The following evaluation items were; compared between transgenic melon plants and non-transgenic melon plants. 1. Morphological characteristics was compared in a closed greenhouse. Fruits maturation period was examined in a semi-closed greenhouse. Morphological characteristics of transgenic melon plants were not different from those of non-transgenic melon plants. Maturation period of the transgenic melon plants was 44.7 days in average and the non-transgenic melon plants was 43.0 days in average. This result demonstrated that transgenic melon plants did not differ from the non-transgenic plants in fruit maturation period. 2. Pollen form and fertility were not different between transgenic and non-transgenic melon plants. Longevity of the pollen from transgenic and non-transgenic melon were examined on fine days in May 1992. Pollen was collected at 9 : 30, 11 : 30, 13 : 30, 15 : 30, 17 : 30 from both transgenic and non-transgenic melon plants, then sowed onto pollen germination medium. Most of the pollen collected at 9 : 30 germinated. Few collected at 13 : 30 germinated, and pollen collected at 15 : 30 did not germinate. Therefore, longevity of the pollen in both transgenic and non-transgenic melon plants seems to be within about 13 : 30 in a closed greenhouse on fine day. 3. Wind pollination of transgenic and non-transgenic melon plants were investigated under artificial wind, generated by an electric fan, in a closed greenhouse. Pollen germination medium were placed at various distance, 0, 5, 10, 15, 50, 100, 200 and 300 cm from the plants. The wind was blown from 10 : 00 to 15 : 30, at a velocity of 0.5-4.0 m/sec. Pollen from transgenic or non-transgenic melon plants were not detected on germination medium at all distance from the plants. We concluded that pollen of melon, an entmophilous plant, dose not disperse by wind, and is generally dispersed only by insects. 4. Seed fertilities of transgenic and non- transgenic plants were 75.5 % and 58.4 %, respectively. We considered that this difference was due to the affection of weakness of non-transgenic seedling. Germination ratios of seeds stored for 0, 6 and 12 months were not different between transgenic and non-transgenic melon. 5. Cross compatibility of melon (Cucumis melo) in Cucurbitaceae was investigated. Pollen of melon were pollinated to female flowers of cucumber, C. angria, C. metuliferus, C. africanus, watermelon, pumpkin, bottle gourd and bitter gourd. Twenty-four hrs after pollination, elongation of pollen tubes in the styles was investigated by staining with aniline blue. Degrees of elongation of pollen tubes were dependent on the female plants. However, the pollen from the non-transgenic melon plants did not fertilize any related species. These results indicated that melon can not fertilize other species than melon. From these results, it is reveled that there was no difference between transgenic melon and non-transgenic melon plants for characteristics of morphology and gene flow.

TAG-PBU. (2004). "Assessing the safety of genetically modified plants for non-target organisms." from http://www.europabio.org/TAG.htm.

A step-wise or ‘tiered’ approach has been used as a rational procedure to conduct environmental risk assessments in many disciplines. The Technical Advisory Group (TAG) of EuropaBio’s Plant Biotechnology Unit (PBU) proposes that the tiered approach also be recognized as the recommended approach to evaluate the environmental safety of GM crops, in particular for potential risks to non-target organisms (NTO). The tiered process allows the ‘case-by-case’ assessment of potential risks of a GM crop to NTO and provides for a logical progression of NTO studies of increasing complexity and refinement where necessary. The tiered approach also allows the practical organization of data generation and enables rational, science-based decision-making by both registrants and regulators.

Tatout, C., S. Warwick, et al. (1999). "SINE insertions as clade markers for wild crucifer species." Molecular Biology and Evolution 16(11): 1614-1621.

Short interspersed nuclear elements (SINEs) are small noncoding transposable elements that are widespread in most eukaryotic genomes. Plant S1 SINEs are present in crucifers, especially in species of the Brassiceae tribe, and were generated by several waves of amplification of different evolutionary ages, suggesting that S1 insertional variability (presence/absence of an S1 at a given genomic site) could be used as a classification criterion to evaluate phylogenetic relationships. We applied this strategy on closely related species from the Brassica oleracea species complex using 21 independent S1 genomic sites. The microsatellite-like variation of S1 3' poly(A) tails was also used as a complementary classification criterion to obtain internal resolution in two different clades. The phylogenetic tree obtained by this approach is in general agreement with the classification made from chloroplast DNA restriction site polymorphisms and differs significantly from two other (nonequivalent) classifications made using nuclear restriction fragment length polymorphisms. Brassica incana Brassica montana, and Brassica hilarionis are confirmed as the closest relatives of B. oleracea. From our data, we suggest that Brassica drepanensis emerged recently from a B. incana/Brassica villosa hybrid (with B. villosa as the maternal patent) following backcrosses to B. incana. We also detected several introgressions, confirming that these highly related species are capable of genetic exchange in their natural habitat. S1 markers are therefore very useful in understanding the detailed evolutionary history of wild Brassica species and could also be used to identify potential gene flow between cultivated (including transgenic) Brassica and their wild relatives.

Tepfer, D., R. Garcia-Gonzales, et al. (2003). "Homology-dependent DNA transfer from plants to a soil bacterium under laboratory conditions: implications in evolution and horizontal gene transfer." Transgenic Research 12(4): 425-437.

DNA transfer was demonstrated from six species of donor plants to the soil bacterium, Acinetobacter spp. BD413, using neomycin phosphotransferase (nptII) as a marker for homologous recombination. These laboratory results are compatible with, but do not prove, DNA transfer in nature. In tobacco carrying a plastid insertion of nptII, transfer was detected with 0.1 g of disrupted leaves and in oilseed rape carrying a nuclear insertion with a similar quantity of roots. Transfer from disrupted leaves occurred in sterile soil and water, without the addition of nutrients. It was detected using intact tobacco leaves and intact tobacco and Arabidopsis plants in vitro. Transfer was dose-dependent and sensitive to DNase, and mutations in the plant nptII were recovered in receptor bacteria. DNA transfer using intact roots and plants in vitro was easily demonstrated, but with greater variability. Transfer varied with plant genome size and the number of repeats of the market DNA in the donor plant. Transfer was not detected in the absence of a homologous nptII in the receptor bacteria. We discuss these results with reference to non-coding DNA in plant genomes (e.g., introns, transposons and junk DNA) and the possibility that DNA transfer could occur in nature.

Thalmann, C., R. Guadagnuolo, et al. (2001). "Search for spontaneous hybridization between oilseed rape (Brassica napus L.) and wild radish (Raphanus raphanistrum L.) in agricultural zones and evaluation of the genetic diversity of the wild species." Botanica Helvetica 111(2): 107-119.

Possible spontaneous gene flow under agricultural conditions was studied between the crop Brassica napus subsp. napus (oilseed rape), as pollen donor, and the common weed Raphanus raphanistrum (wild radish), as mother plant. Conventional cultivars were used. Around 750 individuals of R. raphanistrum were screened by flow cytometry or chromosome counts, and further genetic analysis was performed with random amplified polymorphic DNA (RAPD) on 98 selected plants. No hybrids were detected. The genetic structure of B. napus was uniform over the area investigated, which was expected for a cultivated species. In contrast, R. raphanistrum was genetically variable within populations, while geographical genetic variation among populations within the regions and even among regions was small. It is interpreted as an indication of gene flow sensu lato over large areas caused by seed dispersal by man.

Thies, J. E. and M. H. Devare (2007). "An ecological assessment of transgenic crops." Journal of Development Studies 43(1): 97-129.

Since the first commercial release of a transgenic crop in 1994, the land area planted to these crops has expanded to over 90 million ha worldwide, with approximately 8.5 million farmers in 21 countries cultivating transgenic crops. Public apprehension has mounted apace. Concerns include.- (i) the potential for gene flow into wild plant populations or soil organisms; (ii) adverse effects on non-target organisms; (iii) gene products or crop residues persisting in the environment with deleterious effects and, for insecticidal crops; (iv) resistance developing in target pest populations. Numerous studies on the environmental risks of transgenic crops are published. Geneflow to a crop's wild relatives has been demonstrated in the field; hence, the use of these crops is restricted to regions where wild relatives are not endemic. Geneflow to soil organisms is yet to be demonstrated under field conditions and is unlikely given the safeguards employed, but not impossible. The weight of the evidence suggests that there is little risk to nontarget soil organisms, but reduced numbers of non-target beneficial insects have been reported with the use of insecticidal crops in some systems. Population effects on non-target insects associated with the use of insecticidal crops are significantly less extensive than those experienced using chemical pesticides, and it has yet to be determined if observed population changes are ecologically significant in these cropping systems. Resistance of target pests to insecticidal crops is possible and eventually likely, but after nearly a decade of use has yet to be detected under field conditions. Several strategies to reduce potential ecological impacts are either under development or near release. Ecological risks posed by new technologies under development and the need for in-country; risk assessment and post-release monitoring are discussed.

Thomas, E. and P. D. Nickson (2005). "Environmental release of living modified organisms: current approaches and case studies." Tsitol Genet 39(3): 37-42.

Agricultural biotechnology is being rapidly adopted as evidenced by the acreage of genetically modified (GM) crops planted and tonnes of product (grain and fiber) harvested. Concurrent with this technological progress, is a growing concern that the worlds biological diversity is coming under increasing threat from human activities. As such, ecological risk assessment approaches are being developed for GM crop plants as international agreements regulating the transboundary movements of these products are being implemented. This paper