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United States Department of Agriculture

Agricultural Research Service

Research Project: POTATO GENETICS, CYTOGENETICS, DISEASE RESISTANCE, AND PRE-BREEDING UTILIZING WILD AND CULTIVATED SPECIES

Location: Vegetable Crops Research Unit

2008 Annual Report


1a.Objectives (from AD-416)
Objective 1: Develop adapted potato clones with enhanced resistance to major potato diseases. Sub-objective 1.A. Characterize the molecular genetic basis for late blight (Phytophthora infestans) resistance in the diploid potato species Solanum bulbocastanum. Sub-objective 1.B. Identify resistance genes/factors present within late blight resistant accessions of the diploid wild potato species Solanum verrucosum. Sub-objective 1.C. Develop adapted potato germplasm with high levels of resistance to the fungal pathogen Verticillium dahliae and determine the genetic basis of resistance. Sub-objective 1.D. Identify sources of resistance to early blight (Alternaria solani), common scab (Streptomyces scabies), and soft rot (Erwinia spp., aka Pectobacterium spp.), and introgress them into S. tuberosum. Objective 2: Evaluate exotic potato germplasm for flavor and nutritional components, and introgress valuable genes into the cultivated potato. Sub-objective 2.A. Identify major components of flavor in potatoes and determine the range of variation for those traits in exotic potato germplasm. Relate biochemical variability to sensory analysis data. Sub-objective 2.B. Assess the genetic variability in wild Solanum species for nutritional quality traits including starch composition, antioxidant capacity, and vitamin and mineral levels. Where valuable variation exists, determine the genetic basis of the trait and begin studies to introgress useful genes into the cultivated potato. Objective 3: Examine exotic potato germplasm for resistance to low temperature sweetening and introgress valuable genes into the cultivated potato. Objective 4: Characterize molecular, physiological and environmental parameters that are determinants of potato quality, especially seed vigor and tuber processing quality. Sub-objective 4.A. Characterize molecular and physiological changes that occur in potato tubers that cause, or are tightly linked to, the accumulation of reducing sugars. Sub-objective 4.B. Determine the genetic and physiological basis of tuber vigor across storage times and environments. Sub-objective 4.C. Characterize water relations and respiration of stored potato tubers and determine the range of variation for these parameters in wild and cultivated potatoes.


1b.Approach (from AD-416)
This project focuses on utilizing wild potato germplasm as a source of genes for traits important to potato improvement, such as disease resistance, flavor, nutritional quality, and low temperature sweetening. We will identify novel resistance to major potato diseases in wild relatives of the potato and introgress that germplasm into the cultivated potato. We will also use molecular genetics to characterize resistance mechanisms in wild species and hybrids with the cultivated potato (Objective 1). In addition, we will screen wild and cultivated potato relatives for flavor and nutritional quality traits, and introgress genes for these traits into the cultivated potato. In parallel, we will determine the biochemical components that can be manipulated to improve flavor and nutrition (Objective 2). We will carry out genetic studies to determine the genetic basis of cold sweetening in wild and cultivated potatoes at the diploid level, and introgress selected germplasm into the cultivated potato (Objective 3). In addition, we will carry out studies to determine the physiological basis of tuber vigor and tuber processing quality (Objective 4). Together, the completion of these objectives will lead to the development of potato cultivars that contain increased genetic diversity, require less management and are highly marketable, leading to increased revenue for the U.S. potato industry.


3.Progress Report
The Peer Review process for the Project has been certified by OSQR as complete. Start date of project is 3/20/2008.

cDNAs were screened for proteins interacting with RB, potato seed was prepared for mutigenesis, and R gene analogs amplified Verticillium, soft rot, and late blight screening is underway. Baked potato flavor and low temperature sweetening and respiration were evaluated. This research addresses National Program 301, Plant, Microbial, and Insect Genetic Resources, Genomics and Genetic Improvement, Component II, Genomic Characterization and Genetic Improvement.


4.Accomplishments
1. The Peer Review process for the Project has been certified by OSQR as complete. Start date of project is 3/20/2008.

Testing Taxonomic Predictivity. A study was completed to determine whether taxonomy or geographic parameters could predict the distribution of genes for resistance to Colorado potato beetle (caused by Leptinotarsa decemlineata) in wild Solanum species. The study revealed no association between either taxonomic status or geographic distribution and insect resistance. We also identified novel sources of Colorado potato beetle resistance. This project has identified new sources of resistance to the most significant pest in potato, the Colorado potato beetle. Genes from these species can be introgressed into the cultivated potato to work toward the development of potato cultivars with resistance to the Colorado potato beetle. This will reduce production costs for farmers and have a positive environmental impact by reducing the use of pesticides. This project addresses National Program Component 1 and Problem Statement 1B.


5.Significant Activities that Support Special Target Populations
None.


6.Technology Transfer

None

Review Publications
Bethke, P.C., Jansky, S.H. 2008. The Effects of Boiling and Leaching on the Content of Potassium and Other Minerals in Potatoes. Journal of Food Science. 73(5):H80-H85.

Jansky, S.H., Simon, R., Spooner, D.M. 2008. A test of taxonomic predictivity: resistance to the colorado potato beetle in wild relatives of cultivated potato. Phytopathology. 98:680-687.

Last Modified: 9/10/2014
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