Location: Vegetable Crops Research
2023 Annual Report
Objectives
Objective 1: Efficiently and effectively acquire genetic resources of potato and its wild relatives, maintain their safety, genetic integrity, health and viability, and distribute them and associated information worldwide.
Objective 2: Develop more effective genetic resource acquisition, maintenance, evaluation, and/or characterization methods and apply them to priority genetic resources of potato and its wild relatives. Record and disseminate evaluation and characterization data and digital images via GRIN-Global and other data sources.
Objective 3: With other NPGS genebanks and Crop Germplasm Committees, develop, update, document, and implement best management practices and Crop Vulnerability Statements for potato genetic resource and information management.
Approach
Proven methods and developing needs and technologies will guide the most efficient acquisition of germplasm. Similarly, we will classify the germplasm by assigning species names, and also using other methods to identify pools of diversity useful to germplasm users. Preservation will be accomplished by keeping propagules as botanical seeds and in vitro clones. Optimal storage environments will be used. Germplasm health will be preserved by testing both seed increase parents and offspring for the seed-transmitted viroid, Potato Spindle Tuber Viroid (PSTV). Germplasm will be distributed to requesters in a timely fashion and stocks provided to federal, state, corporate, and private clients in the US and abroad at little to no cost. Data management will be done by staff at the genebank in cooperation with the national computer network for the nation’s germplasm, GRIN. DNA marker data analysis, experimental design, and interpretation will be done by staff on campus. We will make annual collecting trips to the southwest in the fall to collect subject material for DNA marker analysis for various aspects of interest with respect genetic richness and the relationship of diversity in the wild with that in the genebank. Core subsets and populations rich in unique alleles will be identified. Techniques that improve flowering, seedset, and germination useful to both the genebank and germplasm users will be studied. Outreach will be accomplished through the Potato Crop Germplasm Committee (PCGC), Plant Germplasm Operations Committee (PGOC), National Research Support Program – 6 (NRSP6), Germplasm Resources Information Network (GRIN-Global), and by maintaining the genebank website covering all aspects of the project mission.
Progress Report
This is the final report for this project which terminated in April 2023. See the report for the replacement project, 5090-21000-072-000D, “Management of Potato Genetic Resources and Associated Descriptive Information” for additional information.
Objective 1. We completed all aspects of delivering germplasm services to the nation’s researchers and breeders. Several advances were made to improve the security of the germplasm. These include: 1) Replaced failing primary seed cooler and sequestered backup seed samples in a separate fire-proof building, 2) Installed low temp failsafe cutout thermostat in tuber cooler, 3) Converted a duplicate set of the clonal tissue culture collection to microtubers, 4) Adopted true seed Polymerase Chain Reaction - based testing for Potato Spindle Tuber Viroid, 5) Adopted improved germination testing, and confirmed very good germination across the entire seed collection, and 6) Adopted improved lighting and other cultural aspects of plants for seed increase, resulting in greater growth, flowering, and seed yields.
Objective 2. Advances were also made in the characterization and technical use of the germplasm: 1) DNA and phenotype study of populations currently with “unknown” taxonomy, 2) Production of a core collection of 62 diploid cultivated potato lines selected for Late blight resistance, 3) Demonstration of the novel introgression of Solanum jamesii into cultivated forms of potato, 4) Refinement of sample bulking to capture DNA diversity of a population, 5) Validation of a backcrossing scheme to convert rare single-genotype accessions in botanical seed form, 6) Conducted genetic structure analysis of primitive cultivated seed populations to inform best method of seedlot propagation and selections of core collections, and 7) Setup and testing of segregating populations and DNA marker mapping for the tuber rot disease Dickeya, drought tolerance, and Zebra chip disease.
Accomplishments
1. Multiplied genebank stocks. Ideally, no stocks would be lost from the genebank, and all would be available for rapid distribution to germplasm users. The number of viable seeds in seedlots eventually is reduced due to using them for research or declining germination rate. For tissue culture stocks kept in sterile media in test tubes, plantlets show signs of age and may die after about 6 months. Thus, seeds need to be planted out, grown to plants which flower, and hand pollinated to produce a new sample with more seeds of high germination. Tissue culture plants need rejuvenation by transfer to fresh tubes. ARS researchers in Madison, Wisconsin, hand-pollinated 56 families of 20 plants each in greenhouses for seed increase and performed over 3,261 tissue culture transfers to maintain fresh propagules of seed and clonal stocks, respectively. This maintained the availability of seed and tissue culture stocks to support all manner of research and breeding done by the independent users of genebank stocks which will improve the potato crop with respect to disease, pest, stress resistances, yield and quality.
2. Evaluating the US Potato Genbank collection for presence of Potato Spindle Tuber Viroid (PSTV). Ideally, any genebank stocks with PSTV would be identified and quarantined before it could spread within the genebank or be sent to germplasm recipients. PSTV disease is highly contagious and no germplasm recipients want receipts from the genebank to infect their research or breeding programs. ARS researchers in Madison, Wisconsin, applied a new testing technique which is faster and with much greater sensitivity to refine the testing of over 3,500 tests for Potato Spindle Tuber Viroid. This improvement in the monitoring of PSTV allows the genebank to do more rapid and secure distributions of germplasm to those wanting to use it for research and breeding to improve the potato crop.
Review Publications
Bamberg, J.B., Kazmierczak, T.M., Colquhoun, J., Del Rio, A. 2023. Cheatgrass inhibits wild potato (Solanum jamesii) tuber sprouts. American Journal of Potato Research. https://doi.org/10.1007/s12230-022-09903-1.
Cohen, Z., Bamberg, J.B., Schoville, S., Groves, R., Bradford, B. 2023. Colorado potato beetle (Leptinotarsa. decemlineata) prefer Solanum jamesii populations on which they were originally observed in the wild. American Journal of Potato Research. 1-5 (2023). https://doi.org/10.1007/s12230-023-09911-9.
Jenderek, M.M., Ambruzs, B.D., Tanner, J.D., Bamberg, J.B. 2023. High regrowth of potato crop wild relative genotypes after cryogenic storage. Cryobiology. 111:84-88. https://doi.org/10.1016/j.cryobiol.2023.03.006.
Volk, G.M., Carver Jr., D.P., Irish, B.M., Marek, L., Frances, A.L., Greene, S.L., Khoury, C., Bamberg, J.B., Del Rio, A., Warburton, M.L., Bretting, P.K. 2023. Safeguarding plant genetic resources in the United States during global climate change. Crop Science. 63(4):2274-2296. https://doi.org/10.1002/csc2.21003.
Haynes, K.G., Qu, X., Bamberg, J.B. 2022. Germplasm release: true potato seed (TPS) from a late blight resistant, long-day adapted diploid potato population which is segregating for early blight resistance. American Journal of Potato Research. https://doi.org/10.1007/s12230-022-09882-3.
