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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 Research

2013 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. Formerly 5348-21000-018-00D (3/08).

3. Progress Report:
This project was terminated in January of 2013 and replaced with project 5348-21000-025-00D, "Temperate Forage Legume genetic Resource Management, Characterization, and Evaluation". 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 regenerating 250 accessions, and assisting users to select germplasm in our collection. We surveyed alfalfa fields to identify source and sink fields to study Roundup Ready transgene flow in Fresno County, California, Canyon County, Idaho, and Walla Walla County, Washington. We have identified a total of 40 sink fields to study in 2013 and 2014. Pollinator surveys were conducted on sink fields in June, and seed from 1000 individual plants were harvested around the edges of sink fields in August. Progress on this research was reported at the NIFA BRAG Project Director Meeting in June.

4. Accomplishments
1. Documentation of US crop wild relative inventory. Crop wild relatives are very important for crop improvement since they harbor useful genes conferring needed agronomic traits such as stress tolerance and disease resistance. Our paper reporting on the crop wild relative inventory in the United States was published in April and received substantial press coverage. It was the top paper read in the journal Crop Science from June to August 2013. This timely document will be used to assess and prioritize the conservation of genetic resources of wild crop relatives of important crops that occur natively in the United States for future generations, both in natural habitats and in genebanks.

Review Publications
Khoury, C., Greene, S.L., Wiersema, J.H., Maxted, N., Jarvis, A., Struik, P.C. 2013. An inventory of crop wild relatives of the United States. Crop Science. 53:1496-1508.

Last Modified: 08/15/2017
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