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Abstract: Allele-Specific Markers Based within the Stem Rust Resistance Gene (Rpg1) in Barley

 
 
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 The stem rust resistance gene Rpg1 has provided durable resistance to Puccinia graminis f. sp. tritici in barley. An RFLP probe (ABG704) located on chromosome 1 (7H) has been linked with this gene, and has been modified into several PCR-based markers. While these markers recombine with Rpg1 at less than 1%, they misidentify a large number of cultivars in our breeding program as "resistant". With the recent isolation and sequencing of Rpg1 by the Kleinhofs group at Washington State University, it became possible to construct diagnostic primer sets based on variation within the gene. We have developed SCAR markers that differentiate between the functional form of the resistance gene, and 3 altered (susceptible) forms of the gene. Two SCAR markers were designed to specifically amplify the resistant, or susceptible alleles, and can be combined to produce a co-dominant test. In addition, a fourth group of susceptible cultivars that do not have the gene at all can also be identified. The primers have a wide effective annealing temperature range, and can be used to predict the disease reaction of uncharacterized cultivars.

Peter E. Eckstein, Brian G. Rossnagel and Graham J. Scoles
Department of Plant Sciences/Crop Development Centre, University of Saskatchewan, Saskatoon, SK, Canada, S7N 5A8

Presented at the 3rd Canadian Barley Symposium, June 19-20, 2003

  
 
 
 
For more information about the content of this document, contact Lori Oatway.
This information published to the web on October 3, 2003.