Location: Small Grains and Potato Germplasm Research
Project Number: 2050-21000-036-000-D
Project Type: In-House Appropriated
Start Date: Mar 1, 2023
End Date: Feb 29, 2028
Objective:
Potato breeding in the United States is mainly a collaborative undertaking between public institutions with the time necessary to develop new varieties taking up to fifteen years. Molecular techniques, including high throughput marker assisted selection (MAS), can reduce the timeframe. The discovery of new or emerging diseases makes it imperative that resistance be incorporated into potato to reduce losses. Climate changes, historic droughts and the need for lower nitrogen and pesticide inputs also drive the development of new varieties. This breeding program has been in place for more than seven decades with a large germplasm base to draw upon for resistance and quality traits. The program contributes to the Northwest Potato Variety (Tri-State) Program (NPVP) representing collaborations among ARS and land grant universities of Idaho, Oregon, Washington, and the potato commissions of these states. The program has a pipeline of potential new varieties allowing release of one to three varieties each year. Industry is very involved in this program providing input that helps direct research to solve problems and develop ready to use varieties. The end result is varieties with lower environmental impact that economically support, and address industry needs.
Objective 1: Develop and release new potato varieties having traits for improved processing, pest and pathogen resistance, nutrient and water utilization, greater resiliency to environmental stress, and enhanced tuber qualities that benefit the productivity and profitability of the potato industry.
Sub-objective 1.A: Develop potato varieties with improved processing and fresh market traits.
Sub-objective 1.B: Develop potato varieties with improved pest and pathogen resistance.
Sub-objective 1.C: Develop varieties with more efficient nutrient and water utilization and greater resiliency to environmental stress.
Objective 2: Discover and incorporate resistance genes from wild and domestic potato to improve varietal resilience.
Objective 3: Develop and deploy molecular markers to accelerate the improvement of new potato varieties to meet the needs of the potato industry.
Objective 4: Research the biology of new and emerging diseases and pests in potato such as Potato mop-top virus and potato cyst nematodes and incorporate virus and nematode resistance genes.
These objectives will be reached using the dedicated efforts of a Plant Breeder Geneticist, a Molecular Geneticist, and a Plant Pathologist. Together this team with the help of five technicians will use field, greenhouse, and lab resources to execute beneficial trait hybridizations, research disease interactions, seek new molecular markers and obtain and incorporate resistance genes from multiple sources. Within the scope of the project plan’s timeline, up to fifteen new varieties will be released, higher throughput evaluations will be developed to identify and select resistant progeny, and a better understanding of interactions between pests and host resistance genes will be developed.
Approach:
Objective 1 -develop and release improved trait potato varieties. Sub-obj.1a -improve process and fresh market traits by selected hybridizations on russet-skin, round white, red-skin, and specialty types. Modified backcross with different parent clones will be used each cycle to reduce inbreeding depression. First year field selections and subsequent trials for yield, processing, storage, and nutritional qualities will be done as entries progress. Sub-obj.1b -developing pest and pathogen resistance in selections to be done in randomized complete block (RCB) trials for bacterial, fungal, virus and nematode resistance. Sub-obj.1c -development of varieties resilient to environmental stress (nutrient and water) will be done in RCB and split plot trials. Applications of varying amounts of water and nitrogen will mimic commercial center pivot system application. Where research doesn’t result in a new variety, germplasm releases with desirable traits will be useful in multiple breeding programs. Also, increased number of progenies can be developed to allow success. If better host resistance to pests/pathogens is unsuccessful due to low disease pressure, subsequent assays will be done on the most resistant clones. If trials for environmental resilience fail, resistant germplasm in the literature will be incorporated into trials. To increase gains over time more rigorous reduced water/nitrogen regimes will be used.
Objective 2 -discover and incorporate resistance genes to be done by germplasm exchange and backcrossing, including the use of wild diploid species to introgress traits into tetraploid potato. Marker assisted selection will increase breeding efficiencies and be used for mining germplasm for resistant sources. Unsuccessful efforts may arise due to difficulties in obtaining international germplasm or be due to different environmental flowering conditions or male sterility. Project scientists’ knowledge of phytosanitary requirements will help facilitate movement of germplasm. For male sterility, reciprocal crosses can be made with germplasm used as a female parent.
Objective 3 -develop and deploy molecular markers to be done by testing and incorporating applicable markers. Mapping populations will be geno- and phenotyped to discover QTLs associated with targeted traits. If marker development is longer than five years, incorporation of validated markers and development of QTLs for markers will occur.
Objective 4 -researching the biology of new and emerging diseases to be done by using RCB trials in infested fields. Trials will examine variety reaction to Potato mop-top virus (PMTV) and include germplasm screening for resistance. Resistant sources can be hybridized and used to develop segregating populations for genetic studies. For potato cyst nematode (PCN), putative resistant potato lines will be phenotyped in labs with Globodera nematode populations. Difficulties in finding PMTV resistant germplasm/varieties may exist in which other more diverse material will be sought, screened, and hybridized. For PCN, high G. pallida resistance may be lacking. Pyramiding genes should increase overall resistance and provide horizontal resistance.
