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. Conserve, regenerate, and distribute germplasm of specialty crops, current or potential bioenergy crops (e.g., sweet sorghum, switch grass, and Miscanthus), and new genetic stocks generated by genomic research (e.g., assocition mapping projects) with sorghum and other crops.
1b. Approach (from AD-416):
Acquire samples of native warm-season grasses, bioenergy crops, 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. Conserve and distribute genomic research genetic stocks including association mapping populations of sorghum and other crops. Regenerate, conserve, and distribute more than 88,000 accessions of specialty crops, bioenergy crops, and other 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:
A total of 91,259 accessions of 1,548 plant species were maintained in the Griffin plant genetic resources collection. Over 87.8% of accessions were available for distribution to users and over 97.2% were backed up for security at a second location. Bulk seed samples for 67,241 accessions were maintained at -18 C for long-term storage with seed of the remaining accessions stored at 4 C. A total of 32,512 seed and clonal accessions in 946 separate orders were distributed upon request to scientists and educators in 47 U.S. states and 45 foreign countries. Acquisitions made to the collection included 176 sorghum, 230 pepper, 90 warm-season grass, 32 cowpea, 12 peanut, 13 vegetable, and 10 other accessions. A plant collection trip in Alabama, Florida, Georgia, and South Carolina added 39 naturalized Sorghum halepense, 14 switchgrass, and 3 indiangrass accessions to the collection. Seed regenerations and characterization were conducted on 815 peanut, 77 cowpea, 113 warm-season grass, 150 pepper, 301 legume, new, and misc. crop, 127 annual clover, and 32 other vegetable accessions. Peanut accessions were regenerated with cooperators in Georgia, Florida, North Carolina, Oklahoma, and New Mexico. Over 200 pepper accessions were grown in California for characterization and recording of digital images. Digital images of sorghum, cucurbit, cowpea and warm-season grass accessions, and seed oil and fatty acid content of okra and watermelon, peanut core fatty acid content, and sorghum 100-seed weight data were added to the Germplasm Resources Information Network (GRIN). Long-term maintenance of 242 wild peanut and 411 warm-season grass clonal accessions was continued in the greenhouse with an additional 47 napiergrass accessions maintained in the field. A total of 24 bermudagrass and 725 sweetpotato accessions were maintained in tissue culture. Germination testing has been conducted on 73,274 accessions (over 81% of collection) since 2002. In cooperation with industry, differential sets of four vegetable crops were distributed to researchers for identification of disease races. Photoperiod-sensitive Teramnus and annual clover accessions were regenerated in the winter greenhouse. Seed oil content and fatty acid composition was determined for the entire U.S. collections of kenaf, roselle, okra (oil content only), and two pumpkin species. Morphological descriptor, oil content, fatty acid composition, and genetic variability data are being used to develop a core subset from the U.S. castor bean collection. With cooperators in Kansas, a total of 300 sorghum accessions were selected for biomass evaluation in the field from 1,000 accessions genotyped by genotyping-by-sequencing (GBS) analysis. Variation for phytochemicals including flavonol content, oil content, fatty acid composition, and anthocyanin index were determined in lablab, desmodium, roselle, and/or kenaf accessions. Variation in glucose content was found in sunn hemp accessions. Six clonal little bluestem lines were evaluated in the field for ornamental cultivar development. Salt tolerance screening was conducted on the U.S. zoysia collection.