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.

Investigating Parentage and Hybridity of Three Azaleodendrons Using Amplified Fragment Length Polymorphism Analysis

Breeding
The objectives of this study were 1) to elucidate the progenitor species of Rhododendron cultivars ‘Fragrans’, ‘Fragrans Affinity’, and ‘Fragrant Affinity’; and 2) to determine whether these cultivars are all distinct clones or possibly synonyms.

Bred for Success

Breeding
Oregon State University professor Ryan Contreras discusses the Nursery Crop Breeding Program at OSU and the current research being conducted into woody landscape cultivars with reduced invasive potential, increased disease resistance, and increased abiotic stress tolerance.

Protecting Container-grown Plants

Container

Pests and pathogens are a threat for growers that produce containerized nursery stock. The authors discuss how to reduce these threats by considering the type of containers and growing media they use, where they are sourced, how they are handled, and how they are stored.

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