Marker-Assisted Selection of late blight (Phytophthora infestans) resistant potatoes (Solanum tuberosum)

Project Overview

Project Type: Graduate Student
Funds awarded in 2005: $10,000.00
Projected End Date: 12/31/2006
Grant Recipient: University of Wisconsin - Madison
Region: North Central
State: Wisconsin
Graduate Student:
Faculty Advisor:
Jiming Jiang
University of Wisconsin - Madison

Annual Reports


  • Agronomic: potatoes


  • Crop Production: application rate management
  • Education and Training: demonstration, on-farm/ranch research, workshop
  • Pest Management: allelopathy, field monitoring/scouting, genetic resistance, prevention

    Proposal abstract:

    Late blight, caused by Phytophthora infestans, has become an increasing threat to potato production in the recent years due to the introduction of the A2 mating type in North America. In addition, none of the currently grown potato cultivars contain adequate late blight resistance. The method currently used to provide most of the protection is extensive fungicide application. In epidemic years, 15-25 applications may be needed to control late blight. Thus, it is imperative that new materials are produced and that potato growers have access to them in a timely manner. A wild potato species, Solanum bulbocastanum, is highly resistant to all races of P. infestans and has been used in the generation of somatic hybrids. These somatic hybrids have been extensively used in the Wisconsin Potato breeding program. However, there has not been an effective method to accurately assess the late blight resistance of the produced progeny. Therefore, an effective PCR marker was developed to screen out only those progeny containing RB-gene mediated resistance. One hundred and twelve lines have already been screened and a representative sample tested in the greenhouse to confirm the resistant phenotype. This study will continue with the marker selection of first field generation potatoes to bring only those potatoes carrying the RB allele into more advanced breeding. This study will also incorporate a field day and literature alerting the growers and the potato community about future RB potatoes. The information shared will detail how the varieties were developed and how these potatoes will impact the environment through use of fewer fungicides.

    Project objectives from proposal:

    • The short-term results that will be measurable by the end of this project will be a change in the potato grower’s knowledge regarding marker-assisted breeding. Growers will be informed of the marker-assisted selection process used to screen out only RB potatoes in the first generation of selection. A demonstration of how this narrows down the genetic base for the next generation will be performed. Somatic-hybrid development and subsequent breeding line development will be addressed. Growers will also become aware of the differences between somatic hybrids and transgenic or genetically modified potatoes.

    • Intermediate results will be a general understanding of how marker-assisted breeding benefits the grower. They will have an understanding that by using this form of breeding cultivars with important characteristics will be available faster. Growers will have a better understanding of what type of resistance is offered by the RB gene and that less fungicide will need to be used.

    • Long-term outcomes from this project will be potato varieties containing RB-gene mediated late blight resistance.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.