Location: Vegetable Crops Research2020 Annual Report
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.
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.
ARS researchers at Sturgeon Bay, Wisconsin, completed or made good progress on all aspects of delivering germplasm services to the nation’s researchers and breeders as planned for this year. Several promising evaluation studies in the past project have continued and were substantially advanced this year. These include: 1) validation of a particularly large and genetically diverse wild potato population in the United States; 2) characterizing of rooting, heat, and drought vigor; 3) application of Genotyping By Sequencing (GBS) to assess intra-species relationships and heterogeneity; 4) feasibility of breeding an inbred diploid orange-fleshed Criolla cultivar; 5) validation of a self-incompatible artificial version of a bridge species that does not require emasculation to make crosses; and 6) collect new germplasm and summarize 25 years of research and collecting in the southwest United States.
1. Collect germplasm at priority sites in southwest United States. Project staff collected 15 novel samples of germplasm from the wild in Arizona, New Mexico, and Colorado, and began the process of incorporating them into the genebank. This makes new genetic tools available to germplasm researchers and breeders working on improving the crop. These stocks will also be available to study the relationship between plants growing in the wild and what has been captured in the genebank, thus helping us understand how complete the genebank collection is with regard to being a genetic resource of potato improvement.
2. Perform greenhouse botanical seed multiplication. Project staff hand-pollinated 195 families of 20 plants each in the greenhouse for seed increase and performed 19,522 in vitro transfers to maintain fresh propagules of seed and clonal stocks for germplasm requesters, so they will be able to use germplasm to improve the potato crop without delay.
3. Maintain current virus test schedule and records for all seeds and clones. Project Staff did 889 tests for Potato Spindle Tuber Viroid and the six common potato viruses. This helped ensure that the more than 10,000 items the U.S. Potato Genebank sent to germplasm users this year did not infect their programs with diseases.
4. Evaluate traits as instigated by germplasm users, and as recommended by Crop Germplasm Committee. A broad screening identified the species Solanum. kurtzianum (wild potatoes) as a promising source of root vigor and heat and drought resistance. Project staff tested all of the nearly 100 populations in the genebank, identified some outstanding ones, and already made successful crosses into cultivated potato. In partnership with physiologist colleagues, ARS researchers at Madison, Wisconsin, are discovering the mechanism by which these potatoes resist stress in order to supply potato breeders with tools to mitigate the effects of climate change on the potato crop.