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United States Department of Agriculture

Agricultural Research Service

Research Project: Development of Molecular Markers to Identify Different Physiological Races of Pathogens Responsible for Soilborne Diseases of Alfalfa

Location: Plant Germplasm Introduction and Testing

2011 Annual Report


1a.Objectives (from AD-416)
Identify molecular markers specific to Aphanomyces eiteiches Race 1 and 2.


1b.Approach (from AD-416)
Collect fungal isolates from various geographical regions. Extract DNA from each and combine from each respective race (bulked DNA). Use RAPD, SRAP, or other primers to screen for polymorphisms specific to each race. Develop SCAR markers from sequence derived from the latter markers.


3.Progress Report

The objective of this study was to determine if there is a gene present in alfalfa that confers resistance to leaf hopper. Several alfalfa lines with varying degrees of resistance were screened with SRAP primer combinations and RAPD primers. There were several bands that were present in highly resistant plants that were not present in those with lower resistance. Further studies are needed to determine if these bands conclusively indicate a degree of resistance. Confirmation of this relationship will enable use of this technique to rapidly screen alfalfa for resistance to leaf hoppers. This would allow growers a plant that would survive an outbreak in areas where leaf hopper is a problem. Breeding alfalfa plants with resistance to leaf hopper would be beneficial to growers and seed producers as there is a market for resistance at any level. This project contributes to objective 1 in the parent project. The project was monitored by phone and email contact with the cooperators.


Last Modified: 12/18/2014
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