Managing Phytophthora

Plant disease

Oregon State University affiliated author discusses the top 10 tips for preventing disease in nurseries. Specific topics addressed include site selection and drainage, sanitation practices, disease free plant sources, plants in container, and irrigation.

Sudden Oak Death and Phytophthora ramorum

Disease

A comprehensive guide for forest managers, Christmas tree growers, and forest-tree nursery operators in Oregon and Washington on sudden oak death, the disease caused by the recently introduced Phytophthora ramorum.

Confirmation of hyridity using GISH and determination of 18S rDNA copy number using FISH in interspecific F1 hybrids of Tecoma (Bignoniaceaea)

Breeding

This study on interspecific hybridization in Tecoma Juss. was conducted to develop novel forms for the nursery industry. The selection of species used in the study included T. garrocha, T. stans, T. guarume, and T. capensis.

Genetic Methods for Mitigating Invasiveness of Woody Ornamental Plants: Research Needs and Opportunity

Breeding

A review of the different means by which the potential for invasiveness in woody ornamentals can be reduced using genetic methods. Progress is reviewed in conventional breeding and transgenic biotechnology approaches to producing sterile forms of ornamental woody plants.

A Simple Chromosome Doubling Technique is Effective for Three Species of Cupressaceae

breeding

A recent report described a simple technique to double Cryptomeria japonica chromosomes. The objectives of this research was to evaluate the effectiveness of the technique and determine optimal treatment duration for doubling chromosome numbers in oriental arborvitae, american arborvitae, and western red cedar.

An Oryzalin-induced Autoallooctoploid of Hibiscus acetosella 'Panama Red'

breeding

Research was conducted to take advantage of the reduction in plant size and vigor often associated with induced polyploidy. The principle objectives were to induce polyploidy in seedlings from H. acetosella ‘Panama Red’ and to evaluate the effects on growth, morphology, and fecundity.

Oryzalin-induced Tetraploidy in Crytomeria japonica (Cupressaceae)

Breeding

Japanese-cedar (Crytomeria japonica) performs well under a range of soil and environmental conditions but has been underused in landscapes, in part, due to winter browning. In previous studies, chance seedlings that did not exhibit winter browning were identified as tetraploids. This study was conducted to induce polyploidy in Crytomeria japonica.

Sulfuric Acid Scarification of Callicarpa americana L. (Lamiaceae) Seeds Improves Germination

Propagation

An experiment was performed to determine a more effective protocol for germinating C. americana seeds. It was hypothesized that scarification with sulfuric acid would aid in breaking seedcoat dormancy, thereby resulting in more rapid and uniform germination.

Genome Size Estimates and Chromosome Numbers of Callicarpa L. (Lamiaceae)

Breeding
A report on Oregon State University affiliated research, which was conducted with the purpose of documenting chromosome number and genome size of Callicarpa species to add to the available information on the genus.

Reproductive Behavior of Diploid and Allotetraploid Rhododendron L. 'Fragrant Affinity'

Breeding
This study was conducted to evaluate the fertility of diploid and allotetraploid forms of Rhododendron L. 'Fragrant Affinity' and to determine if induced polyploidy is an effective method for restoring fertility in hybrids of distantly related rhododendrons.

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