CAPS and DHPLC Analysis of a Single Nucleotide Polymorphism in the Cytochrome <i>b</i> Gene Conferring Resistance to Strobilurins in Field Isolates of <i>Blumeria graminis</i> f. sp. <i>hordei</i>

Abstract

Abstract A single nucleotide polymorphism in the wheat powdery mildew ( Blumeria graminis f. sp. tritici ) cytochrome b gene is responsible for resistance to inhibitors of the quinol outer binding site of the cytochrome bc 1 complex (QoI) fungicides. Analysis of a partial sequence of the cytochrome b gene from field isolates resistant and sensitive to QoI fungicides revealed the same point mutation in barley powdery mildew ( B. graminis f. sp. hordei ). Analysis of 118 and 40 barley powdery mildew isolates using a cleaved amplified polymorphic sequence assay and denaturing high performance liquid chromatography, respectively, confirmed that this single nucleotide polymorphism also confers resistance to QoI fungicides in barley powdery mildew.