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United States Department of Agriculture

Agricultural Research Service

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Location: Floral and Nursery Plants Research

Project Number: 1230-21000-137-00-D
Project Type: In-House Appropriated

Start Date: Dec 27, 2010
End Date: Apr 3, 2013

1) Strategically expand and improve germplasm collections and associated information for priority woody landscape plant taxa. Priority taxa for collecting include Carpinus, Celastrus, Cercis, Celtis, Cladrastis, Clethra, Cornus, Cotinus, Hamamelis, Hydrangea, Magnolia, Ostrya, Stewartia and Viburnum. With the American Public Gardens Association, coordinate, extend, and strengthen the North American Plant Collections Consortium’s continent-wide ornamental plant germplasm conservation program. 2) Strategically conserve and regenerate National Plant Germplasm System (NPGS) woody landscape plant germplasm efficiently and effectively and distribute samples and associated information worldwide. Regenerate, store, and/or maintain in situ plantings of priority germplasm and associated information, emphasizing Cornus florida, native Magnolia, and selected Viburnum species. Continue to increase to more than 40 percent the proportion of germplasm backed up at second sites, emphasizing critical back-ups. Develop monitoring methods and periodically assay the viability, health and vigor of stored germplasm. Distribute on request accessions and information that meet the specific needs of researchers, breeders, and growers. 3) Strategically characterize and evaluate priority NPGS woody landscape plant germplasm for key traits, such as taxonomic identity, genetic variability, invasiveness, and ornamental merit, thereby enhancing their utility to users, and the effectiveness of germplasm management. Incorporate that information into GRIN. In cooperation with other ARS and university collaborators, develop and apply new genetic markers for taxonomic identity, genetic diversity analyses, and population genetic structure for native Fraxinus species, Cornus florida, and Corylopsis. Ensure that Acer accessions in repository, especially those collected during North America-China Plant Exploration Consortium expeditions, are correctly identified taxonomically and adequately documented. Update and apply phenotypic descriptors for Acer, Halesia, Ilex, Viburnum and other priority taxa via in-house and cooperative evaluation. Incorporate phenotypic evaluation data into GRIN and/or other databases. Introduce especially noteworthy or valuable material to the public via a formal germplasm release.

Collect, propagate, and establish sexual and vegetative propagules of priority germplasm. Use in-house, contracted, and collaborative collectors, focusing on threatened, disjunct, or unique provenances. Train field reviewers, develop regional recruiters and mentor network for public garden participation in national collections program. Coordinate collections of priority genera with national collections holders to fill gaps in germplasm availability and diversity and minimize duplication. Preserve orthodox seed in medium (for distribution) or long term (cryogenic) storage facilities. Maintain recalcitrant species in short term or active collections, or distribute to backup or remote-site locations. Regenerate seed of living collections for distribution, medium and long term storage, using artificial pollinations and pollination cages. Monitor and assay viability of older seed accessions; use Cornus florida accessions to test viability using seed moisture content, seed viability equations as a proxy for other similar stored genera. Maintain current availability lists of germplasm for distribution; coordinate with national arboretum main collections; upload GRIN data on a regular basis for new accessions and matriculating germplasm from active collections. Screen Fraxinus species collected by USDA-ARS North Central Regional Plant Introduction station for ploidy levels; compare morphology and test new species hypotheses. Test cross amplification of Chionanthus-derived SSR markers for utility in Fraxinus germplasm. Use SSR markers from Cornus florida to test diversity levels from edges of species range with previously identified genetic clusters; adjust collecting areas as needed to maximize diversity. Screen Corylopsis germplasm for ploidy level and use AFLP to determine level of hybridization and species identifications. Collect voucher specimens of all Asian Acer taxa for verifying identification; cross-reference with other collections to determine collection gaps and rare taxa. Update GRIN data for priority genera; include descriptors for invasiveness using appropriate models. Propagate and distribute elite material to nursery collaborators for evaluation and introduction.

Last Modified: 06/25/2017
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