Relationship Between Virulence Variation and DNA Polymorphism in<i>Puccinia striiformis</i>

Abstract

One-hundred, fifteen single-urediospore isolates from 23 collections (five isolates per collection) of Puccinia striiformis f. sp. tritici (stripe rust of wheat) selected to represent different regions in North America and different virulence patterns were analyzed for variation in virulence and DNA polymorphism. Virulence characterization was based on the expression of infection types on 15 wheat cultivars used to differentiate races of P. striiformis in North America. Of the 23 collections, 20 had uniformly different virulence patterns, i.e., each of the 20 collections was a different race, and all five isolates of each collection had the same virulence pattern. Two collections consisted of isolates with two virulence patterns, and one collection consisted of isolates with three virulence patterns [...]