Location: Plant Genetic Resources Conservation Unit
2018 Annual Report
Objectives
1. Efficiently and effectively acquire, distribute, and maintain the safety, genetic integrity, health, and viability of priority grain, oilseed, vegetable, subtropical and tropical legume, and warm season grass genetic resources and associated information.
1.A. Acquire genetic resources to expand the diversity of priority crops and crop wild relatives (CWR) available from the genebank via collection, exchange or other appropriate means.
1.B. Conserve and maintain over 94,000 accessions of priority genetic resources and their associated information, periodically assess these priority genetic resources for viability, trueness to type, and health, and distribute accessions upon request.
1.C. Conduct field and greenhouse regenerations of priority crops and CWR to replenish and safeguard high quality genetic resources in state-of-the-art genebank.
2. Develop more effective genetic resource maintenance, evaluation, or characterization methods and apply them to priority grain, oilseed, vegetable, subtropical and tropical legume, and warm season grass genetic resources. Record and disseminate evaluation and characterization data via GRIN-Global and other data sources.
2.A. Using phenotypic descriptors, evaluate priority crops and CWR for agronomic and horticultural traits and incorporate this data into GRIN-Global.
2.B. Develop and apply nuclear magnetic resonance (NMR), rapid N exceed [nitrogen/protein] analyzer (RNEA), high performance liquid chromatography (HPLC), gas chromatography (GC), and gas chromatography-mass spectrometry (GC/MS) procedures to evaluate variation in oil, protein, sugar content, amino acid composition, fatty acid composition, flavonoids, flavors, and other key phytochemicals in priority crops and CWR and incorporate this data into GRIN-Global.
2.C. Develop and apply DNA markers to assess phylogenetic relationships, genetic diversity, population structure, and association with phenotypic traits of priority crops and CWR. Enter DNA genetic marker characterization data into GRIN-Global or other databases (such as GenBank).
3. With other NPGS genebanks and Crop Germplasm Committees, develop, update, document, and implement best management practices and Crop Vulnerability Statements for priority grain, oilseed, vegetable, subtropical and tropical legume, and warm season grass genetic resource and information management.
Approach
Curators will acquire plant genetic resources from collection trips, donations, and exchanges with other gene banks and state universities to adequately conserve the range of crop genetic diversity. Seed from each accession maintained in the collection will be preserved in cold storage to optimize long-term seed viability and reduce the frequency of regeneration. Efforts will continue to conduct standard germination tests on the entire range of crop and crop wild relative accessions in the germplasm collection with emphasis on testing new material and retesting select inventories at ten year intervals. Plant genetic resources (seeds, in-vitro cultures, plants, cuttings, corms, and rhizomes) and associated information will be sent to users worldwide in response to requests received by email, internet, phone, and U.S. mail. Accessions with low seed viability, low seed numbers, original seed only, and age of seed will be targeted for regeneration. Curators will observe and collect phenotypic data using descriptors for each of the accessions/crops grown for regeneration or evaluation. Additional descriptors on classification, local adaptability, and other traits of agricultural importance will be recorded as opportunity permits. Valuable biochemical traits such as oil/fatty acid and protein/amino acid content in oil seed crops; flavonoids and anthocyanins in legumes; flavor and resveratrol in peanuts; protein content in Vigna; protein and mineral content in pearl millet seeds; and fruit color and flavor components in pepper (Capsicum spp.) will be collected, analyzed and made available on the Germplasm Resources Information Network (GRIN-Global). Genetic characterization and evaluation of plant germplasm will be conducted. For genetic characterization of little bluestem, sweet potato and pepper, previously published simple sequence repeat (SSR) markers are available and will be utilized as the focus of the research is not on marker development but rather characterization. For peanut and sorghum, where advanced genomic tools are available, single nucleotide polymorphism (SNP) markers will be used for characterization, association analysis, and design of functional DNA markers. Curators will consult with Crop Germplasm Committees (CGCs) to develop, update, document, and implement Best Management Practices (BMPs) and Crop Vulnerability Statements (CVS) for crops conserved in the genebank. All data including passport, regeneration, and characterization data will be submitted electronically to the Information Technology Specialist or Seed Storage Manager and their designated staff for local storage and uploading to the GRIN-Global database.
Progress Report
A total of 99,851 accessions of 1,596 plant species of 269 genera were maintained in the Griffin plant genetic resources collection. Over 84% of accessions were available for distribution to users and over 97% were backed up for security at a second location. Bulk seed samples for 83,671 accessions were maintained at -18 degrees C for long-term storage with seed of the remaining accessions stored at 4 degrees C. A total of 49,717 seed and clonal accessions were distributed upon request to scientists and educators worldwide in calendar year 2017 and another 24,081 distributed so far in 2018. Long-term clonal maintenance of 188 wild peanuts, 435 warm-season grasses, and 96 bamboo accessions was continued in the greenhouse or field. Seven hundred and fifty-five (755) accessions of sweetpotato were maintained in vitro (or in the greenhouse) and serially recultured, as necessary. Cultures were backed up in Fort Collins, Colorado and distributed on request. Additional cultures were provided to the Fort Collins location in support of their long-term (liquid N) cryopreservation project. Germination testing has been conducted on 86,306 accessions in total. Of those, 2707 seed inventories were pulled for viability testing in 2017 and 521 for 2018.
A total of 1224 seed samples were selected for regeneration this season. Peanut accessions with low seed inventories were planted in Byron and a total of 457 accessions were shelled, cleaned, packaged and submitted to the seed storage laboratory for processing to add to the national collection. A total of 47 miscellaneous, guar, sesame, and legumes originating from low viable seeds were regenerated in Griffin, Georgia plus 41 adzuki bean, rice bean, and Vigna vexillata with low seed numbers were increased in collaboration with ARS scientists at Parlier, CA. In addition, 17 images from Vigna accessions regenerating in Parlier, CA were obtained. Thirty Pepper Mild Mottle Virus (PMMV) infected accessions of Capsicum chinense spp. were increased in the greenhouse for production of ‘clean’ seed. Digital images of these were recorded. Accessions of vegetable crop accessions were regenerated/phenotyped in collaboration with Monsanto/Seminis in Woodland, California, USDA/ARS - Parlier, California, USDA/ARS - Charleston, South Carolina, and USDA/ARS - Mayaguez, Puerto Rico. Critically low inventory accessions of Capsicum were regenerated in the greenhouse in Griffin. Accessions of Citrullus spp., cucurbits (misc. genera and spp. including squash and gourds), and accessions of okra and related Abelmoschus spp., were regenerated in the field or greenhouse.
Approximately 80% of the sweetpotato collection was genotyped in collaboration with ARS scientists in Charleston, South Carolina and researchers at North Carolina State University. An evaluation of the insect resistance characteristics of Citrullus spp. was initiated in collaboration with ARS scientists in Charleston, South Carolina. Work continues to compare sweetpotato germplasm held at both CIP (Lima, Peru) and in the NPGS to attempt to identify genetic changes and or mis-labeled plant materials. Genomic studies in Ipomoea batatas and its related species was continued earlier in this period. Collaborated with ARS scientists in Charleston, South Carolina on evaluation of sweetpotato for leaf characteristics. Capsicum germplasm was evaluated for various fruit quality attributes including sugars, dry weight, and pungency in collaboration with scientists at the University of Maine and ARS scientists at Fort Pierce, Florida. Extraction methods were evaluated for capsiate from fresh fruit of pepper in collaboration with ARS scientists at Oxford, Mississippi.
Second year studies were completed for sennosides from leaves of 4 Senna species; protein, and lignans from seeds of 8 sesame accessions; and anthocyanins and flavonols from seeds of 38 cowpea accessions. Leaves from four Senna species were evaluated for sennoside A and B content and results ranged from 0 to 16.19 mg/g. Two accessions produced the most protein (21.7%) while two black seeded accessions produced the most sesamin (9 mg/g) and sesamolin (6.3 mg/g). Significant levels of anthocyanins and flavonols (ranging from 0 to 1,378 µg/g) were observed in 38 cowpea accessions. This information will be useful for developing high sennoside containing Senna genotypes, high protein and lignan genotypes from sesame and high anthocyanin and flavonol genotypes from cowpea for use as functional health vegetables and laxatives. In collaboration with a start-up company, Pride Road, Inc., roselle production was evaluated for the best accessions to use in jelly and chutney processing.
Analysis of oleic acid in cultivated peanut shows the oleic acid content is related to geographic locations. Fifty-two high oleate peanut accessions were selected and grown in three locations (Georgia, Florida, and New Mexico) in two replicates. Seeds were harvested and used for fatty acid and oil analysis in 2017. For the second year (2018), the same experiment was repeated and seeds have been planted in three locations. At the same time, these 52 peanut lines were also genotyped with FAD2A and FAD2B markers. Four sesame M5 lines and one M6 lines (104 plants total) were planted in greenhouse. The collected seeds were quantified for the levels of oleic acid in 2017. Ten high oleate sesame lines (M5-M6) were selected and planted in the greenhouse for chemical analysis in 2018. In addition 14 high stearic acid (C18:0) peanut accessions were planted in the field for confirmation of the results in 2018. Biochemical characterizations were conducted on the following: 510 peanut samples (314 wild and 200 cultivated) were measured for oil content in triplicates; 1629 samples (314 wild and 465 cultivated peanuts, 850 sesame) were measured for fatty acids in duplicates; 390 samples (314 wild peanut, 31 sesame, and 45 Vigna) were measured for protein content in duplicates; 130 peanut samples were measured for amino acids in duplicates; 50 sweet sorghum and sugarcane samples were measured for sugar content in duplicates; and 32 sesame samples were measured for sesamin and tocopherol content in duplicates. In collaboration with ARS scientists in Tifton, Georgia, peanut seed dormancy from 148 recombinant inbred lines (RIL) generated from the T population plus two parents were determined. In collaboration with ARS scientists in Lubbock, Texas, 256 EMS-induced mutant lines were evaluated for low-phosphorus tolerance at the lab conditions. DNA markers were developed from chloroplast and FAD2 genes in peanut. These DNA markers are being used for characterization of 25 peanut wild species. FAD2 DNA markers is also developed for genotyping some selected sesame mutant lines and germplasm accessions.
Accomplishments
