1a. Objectives (from AD-416)
Objective 1: Strategically expand the genetic diversity in genebank collections and improve associated information for priority Medicago, Trifolium, and Lotus genetic resources. Sub-objective 3C In cooperation with U. S. and Russian researchers, produce an Interactive Agricultural Atlas of Russia and Neighboring Countries which will be accessible on the internet and on CD-ROM. Sub-objectives 1A. Acquire samples and associated information to fill identified gaps in the NPGS collections of Medicago, Lotus, and Trifolium. Sub-sub-objective 1A1. Collect or obtain from the United States, the Mediterranean Basin, and Central Asia, targeted species. Sub-sub-objective 1A2. Survey existing holdings of Medicago truncatula genetic stocks (a model species for legume genomics) and acquire priority materials. Sub-objective 1B. Identify and establish in situ sites for endemic species of Lotus, and Trifolium. Sub-sub-objective 1B1. In cooperation with the U. S. Forest Service and other public land agencies, survey and identify in situ seed collection sites. Sub-sub-objective 1B2. Using a model trifolium species, define in situ conservation parameters needed for outcrossing, insect-pollinated wild legume species. Sub-objective 1C. Based on earlier research, collaborate with Kazakh researchers to identify and establish sites in Kazakhstan for in situ conservation of wild relatives of alfalfa. Objective 2: Conserve and regenerate priority Medicago, Trifolium, and Lotus genetic resources efficiently and effectively, and distribute pathogen-tested samples and associated information worldwide. Sub-objective 2A. Regenerate, conserve, and distribute more than 12,000 accessions of temperate forage legume genetic resources and associated information, emphasizing accessions with low germination, open-pollinated seed stocks, few seeds in storage, or those not yet backed-up at second sites. Sub-objective 2B. Increase to 90 percent the proportion of the collection backed-up at second sites, emphasizing critical back-ups of Medicago, Trifolium, and Lotus. Sub-objective 2C. Regenerate 150-300 accessions of Medicago, Trifolium, and Lotus per year, emphasizing controlled pollination of original or “next best” seed lots for Trifolium and Lotus, so as to systematically replace open-pollinated seed lots. Objective 3: Strategically characterize (“genotype”) and evaluate (“phenotype”) priority Medicago, Trifolium, and Lotus genetic resources for molecular markers, morphological descriptors, and key agronomic traits. Sub-objective 3A. With cooperators, apply newly developed DNA genetic marker data to phylogenetic and genetic diversity analyses of priority crops, especially M. truncatula, to develop core subsets. Incorporate characterization data into the Germplasm Resources Information System (GRIN) and/or other databases. Sub-objective 3B. Update and apply phenotypic descriptors for forage legume collections with an emphasis on capturing key floral, fruit, and seed characteristics of regenerated germplasm, and characterizing forage nutrient value.
1b. Approach (from AD-416)
Acquisition of new germplasm for these genera will be achieved via plant exploration/collecting and germplasm exchange. On the ground surveys of the Blue Mountains will continue to identify key areas where in situ collection sites can be designated for multiple Trifolium species. Accessions being regenerated will be evaluated for basic descriptors in the field; data will be placed in GRIN. Field evaluations will occur during the flowering year, which is usually the seedling year. Molecular markers will be used for identifying genetic diversity within and among accessions, identifying geographical or environmental associations, and assisting in identification of redundancy and gaps in collections. Formerly 5348-21000-018-00D (3/08).
3. Progress Report
This progress report addresses the work conducted by the National Temperate Forage Legume Germplasm Resources Unit in Prosser, WA. The project focuses on the problem of effectively maintaining and charactering a large germplasm collection in order to enhance the use and conservation of these important genetic resources and aligns with National Program 301 Action Plan Component 1: Plant and Microbial Genetic Resource Management. Problem Statement 1A: Efficiently and Effectively Manage Plant and Microbial Genetic Resources.
1. Germplasm maintenance of forage legumes. Forage legume crop diversity is vital for developing high yielding varieties to support the livestock industry in the United States. ARS researchers at the National Temperate Forage Legume Germplasm Unit in Pullman, WA maintained, characterized and distributed germplasm from the 15,000 accession collection. The Unit increased 367 accessions and completed germination tests on 300 accessions, obtained digital images on over 350 accessions and distributed 355 seed packets of Lotus, representing 29 different species; 1832 seed packets of requests for Medicago, representing 53 different species, and 854 requests for Trifolium, representing 21 different species. These activities have provided seed to support research around the world, and conserve important crop biodiversity for future generations.
2. Acquiring important legume germplasm to support genomics research. Medicago truncatula is being used as a model legume species in genomic research, but ex situ collections do not include representation from all areas where the species grows. ARS researchers at the National Temperate Forage Legume Germplasm Unit in Pullman, WA went to the Crimean Peninsula, in Ukraine to collect seed representing germplasm from the northern-most range. Although we did not encounter the species, we collected over 250 seed samples of important forage legume genetic resources. These new resources may provide breeders with useful traits such as cold tolerance and salt tolerance.