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United States Department of Agriculture

Agricultural Research Service

Research Project: Acquisition, Evaluation and Conversation of Temperate Forage Legume Genetic Resources

Location: Plant Germplasm Introduction and Testing

2012 Annual Report


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.


3.Progress Report:
This progress report addresses the work conducted by the National Temperate Forage Legume Germplasm Resources Unit in Prosser, Washington. The project focuses on effectively acquiring, maintaining, characterizing and distributing 15,000 accessions of temperate forage legume germplasm, 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. During the year we focused on regeneration, acquisition and distribution activities in the Medicago, Trifolium and Lotus germplasm collections. We conducted surveys of roadside alfalfa in Fresno, County, California, Canyon County, Idaho, and Walla Walla County, Washington, and tested collected leaf and seeds for the presence of the Roundup Ready transgene. Preliminary results were reported at the ARS Advisory Council meeting and various alfalfa industry meetings. An unfunded specific cooperative agreement between 3 Russian institutes and the ARS was developed to outline IP rights and website maintenance of the AgroAtlas. Morphological and SSR data was obtained on 200 alfalfa wild relatives in collaboration with the Noble Foundation, Ardmore, Oklahoma. To minimize transgene contamination, 160 new cages were built, and sentinel alfalfa fields were monitored for transgene presence. A study to assess the feasibility of moving the alfalfa regeneration location from Prosser to Central Ferry, Washington, was concluded.


4.Accomplishments
1. Forage legume germplasm maintenance, characterization and distribution. Over time, seed inventories decline in gene banks due to natural seed aging and seed distributions to support research and breeding efforts. Due to the deregulation of genetically engineered alfalfa, we are also concerned about maintaining the purity of our seed stocks. ARS researchers at the National Temperate Forage Legume Germplasm Resources Unit in Prosser, WA, grew out 205 accessions to pieces of seed stocks, tested seed viability of 160 accessions and gathered over 2,500 observation data. One hundred and sixty new cages were built and we sampled 17 surrounding hay fields around the Prosser regeneration site to monitor for the presence of the Roundup Ready Alfalfa (RRA) transgene. A feasibility study to explore moving our seed increase site to a more isolated location at Central Ferry, WA, determined that seed production is comparable at both sites, but that a new pole barn and greenhouse need to be built to support forage legume regeneration at Central Ferry. In 2012 we distributed 86 trefoil (Lotus), 1492 alfalfa (Medicago), and 173 clover (Trifolium) accessions. Efforts by ARS researchers at Prosser, WA, ensure the temperate forage legume germplasm collection continues to serve as a resource to researchers and breeders around the world.


Review Publications
Greene, S.L., Afonin, A.A., Dzyubenko, E., Dzyubenko, N. 2012. Effective conservation of Medicago Crop Wild Relatives in Russia and neighbouring countries: a gap analysis points the way forward. Agrobiodiversity Conservation: Securing the diversity of Crop Wild Relatives and Landraces. p.82-90.

Last Modified: 8/19/2014
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