Location: Vegetable Crops Research2021 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 and technical research studies have also continued and substantially advanced this year. These include: 1) testing tissue sampling methods for DNA analysis; 2) characterizing heat and drought tolerance; 3) application of Genotyping By Sequencing (GBS) to assess intra-species relationships and heterogeneity; 4) exploring the 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; 6) collecting new germplasm; 7) Testing alternate options for expanding seed and tuber regeneration.
1. Collect germplasm at priority sites in southwest United States with little prior geographic representation. ARS researchers at Madison, Wisconsin, collected two novel samples of germplasm from the wild in Colorado where wild potato is very rare and incorporated them into the genebank. We assume geographic rarity associates with novel, valuable genetics. Thus new germplasm has been made available to researchers and breeders working on improving the crop. This is similar to stocking a toolbox with an expanded diversity of tools so we have a better chance of fixing problems in the crop, perhaps those not even known yet. These stocks will also be available to study the relationship between plants growing in the wild and those in the genebank, thus helping us understand how complete the genebank collection is with regard to being a genetic resource of potato improvement.
2. Greenhouse botanical seed and clonal multiplication. ARS researchers at Madison, Wisconsin, hand-pollinated 155 families of 20 plants each in a greenhouse for seed increase and performed 18,352 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. ARS researchers at Madison, Wisconsin, completed 1,225 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. ARS researchers at Madison, Wisconsin, assisted specialist researchers in their study of a variety of important potato diseases, pests and stresses. For example, researchers made novel populations and propagules for study of Dickeya, an emerging serious tuber rot disease, Zebra Chip, an emerging bacterial disease vectored by an insect that results in reduced yield and tubers with unacceptable mottled chips; evaluated for natural resistance for Colorado Potato Beetle, the most important insect pest of potato which otherwise requires expensive and toxic pesticide applications; and found large differences among potato species for response to heat stress, a quality that promises to allow the potato crop to be productive even if grown in regions that become hotter due to climate change. Whatever the specific trait needed, the goal is to give researchers and breeders genetic tools to “build in” to the potato crop to keep the high quality, quantity and economy needed by the U.S. consumer.
Bamberg, J.B., Del Rio, A. 2020. Assessing under-estimation of genetic diversity within wild potato (Solanum) species populations. American Journal of Potato Research. 97:547-553. https://doi.org/10.1007/s12230-020-09802-3.
Del Rio, A.H., Bamberg, J.B. 2020. Detection of adaptive genetic diversity in wild potato populations and its implications in conservation of potato germplasm. American Journal of Plant Sciences. 11:1562-1578. https://doi.org/10.4236/ajps.2020.1110113.
Del Rio, A.H., Bamberg, J.B. 2020. A core subset of the ex situ collection of S. demissum at the US Potato Genebank. American Journal of Potato Research. 97:505–512. https://doi.org/10.1007/s12230-020-09799-9.
Bamberg, J.B., Kielar, A., Del Rio, A.H., Douches, D. 2021. Making hybrids with the wild potato Solanum jamesii. American Journal of Potato Research. 98:187-193. https://doi.org/10.1007/s12230-021-09828-1.
Kinder, D., Bamberg, J.B., Louderback, L., Pavlik, B., Del Rio, A.H. 2021. Solanum jamesii as a food crop: history and current status of a unique potato. In: Yildiz, M. and Ozgen, Y., editors. Solanum tuberosum - a Promising Crop for Starvation Problem. London: IntechOpen. p. 1-10. Available: https://doi.org/10.5772/intechopen.98414.
Bamberg, J.B., Del Rio, A. 2021. A metric for species representation in the US Potato Genebank. American Journal of Potato Research. 98:263-265. https://doi.org/10.1007/s12230-021-09833-4.