1a. Objectives (from AD-416)
Strategically expand the genetic diversity in genebank collections and improve associated information for priority vegetable, sorghum, peanut, subtropical/tropical legume, and warm-season grass genetic resources. Conserve and regenerate priority vegetable, sorghum, peanut, subtropical/tropical legume, new crop, and warm-season grass genetic resources efficiently and effectively, and distribute pathogen-tested samples and associated information worldwide. Strategically characterize (“genotype”) and evaluate (“phenotype”) priority vegetable, sorghum, peanut, subtropical/tropical legume, and warm-season grass genetic resources for molecular markers, morphological descriptors, and key agronomic or horticultural traits such as biochemical content and product quality.
1b. Approach (from AD-416)
Acquire samples of native warm-season grasses, subtropical legumes, Ipomoea species, chile pepper, and annual clovers to fill current gaps in NPGS collections. Survey existing holdings of sorghum genetic stocks, identify material that would fill gaps in NPGS collections, and begin acquiring and characterizing them. Regenerate and conserve more than 86,000 accessions of priority genetic resources and associated information. Increase the number of sweetpotato and warm-season grass clonal accessions maintained in tissue culture. Increase to 95 percent the proportion of the collection backed up at second sites. Develop superior regeneration methods for seed and clonally-propagated crops. Assay stored genetic resources for vigor, viability, and health. Distribute on request accessions and information that meet the specific needs of researchers and breeders. Develop and apply new genetic markers for phylogenetic and genetic diversity analyses of priority crops. Update and apply phenotypic descriptors for vegetables, peanuts, warm-season grasses, and subtropical/tropical legumes. Develop, enhance, and/or apply high performance liquid chromatography (HPLC) procedures for analyzing variation in flavonoids, antioxidants, capsaicin, and other key phytochemicals in accessions. Incorporate characterization, phenotypic, and biochemical data into GRIN and/or other databases.
3. Progress Report
This project replaced 6607-21000-009-00D in late April 2008. Progress for most of Fiscal Year 2008 is reported in the annual report for project 6607-21000-009-00D and only progress since late April 2008 will be reported for this project. No milestones in this project were developed for any period shorter than 12 months, so progress for the first milestones of this project will be reported in the next annual report. Progress since late April 2008 relating to National Program 301 Plant Genetic Resources, Genomics, and Genetics Improvement, Component 1 Plant and Microbial Genetic Resource Management, Problem Statement 1A Efficiently and Effectively Manage Plant and Microbial Genetic Resources. Since April 2008, a total of 13,308 seed, tissue culture, and clonal accessions were distributed in 454 orders to researchers and educators throughout the United States and world. Curators conducted regeneration of accessions that were unavailable, had low viability, or were in demand by users. Regenerations of subtropical/tropical legume, peanut, pepper and other vegetable, annual clover, cowpea, and warm-season grass accessions are currently underway. Germination tests continue to be conducted on accessions with tests completed on 48,852 accessions since 2002. Progress since late April 2008 relating to National Program 301 Plant Genetic Resources, Genomics, and Genetics Improvement, Component 1 Plant and Microbial Genetic Resource Management, Problem Statement 1B Assess the Systematic Relationships and Genetic Diversity of Crop Genetic Resources. Phenotypic characterization was conducted on all accessions that were regenerated. Additional characterization included 120 pepper and 236 warm-season grass accessions for phenotypic descriptors, 200 pepper accessions for capsaicin and dihydrocapsaicin content, 50 peanut accessions for oil and fatty acid composition, 21 legumes for anthocyanin index, 7 Hibiscus spp. for flavonol composition, and 48 castor bean accessions for oil content. Sweet sorghum accessions have been genotyped with 50 DNA markers and use of additional markers is underway. Sorghum mutant lines obtained from cooperators have been tilled by ten candidate genes to trace genotype mutation to phenotype. Protocols have been developed to detect sweetpotato leaf curl virus using real-time polymerase chain reaction (PCR) and DNA extraction for evaluation of the entire sweetpotato collection for detection of this virus is in progress. Tomato spotted wilt virus was detected in accessions of an African clover, Trifolium tembense, in the greenhouse. Study of the relationship of leaf spot infection with resveratrol content in peanut accessions has been attempted, but leaf spot inoculation of seedlings was unsuccessful.
1. Castorbean Oil Variation. Limited information is available for genetic variation for seed oil content among the castorbean accessions within the U.S. collection. When grown in one environment at Griffin, GA, significant variation in oil content was found among 48 castorbean accessions. Several castorbean accessions were identified with high oil content and will provide breeders and scientists with valuable castorbean germplasm to fully exploit oil content for use as biodiesel fuel. National Program 301 Plant Genetic Resources, Genomics, and Genetics Improvement, Component 1 Plant and Microbial Genetic Resource Management, Problem Statement 1B Assess the Systematic Relationships and Genetic Diversity of Crop Genetic Resources.
5. Significant Activities that Support Special Target Populations
Dida, M., Wanyera, N., Harrison Dunn, M.L., Bennetzen, J., Devos, K. 2008. Population Structure and Diversity in Finger Millet (Eleusine coracana) Germplasm.. Tropical Plant Biology 1: 131-141.