Chromosomal Localization of the Gene for Resistance to Powdery Mildew in the Wheat Cultivar Wennong 14

Abstract

Wennong 14 is a facultative wheat cultivar commercialized in Shandong province and the neighbouring provinces in the northern part of Yellow and Huai River Valleys Facultative Wheat Zone in China. In this study, an array of Blumeria graminis f. sp. tritici(Bgt) isolates was used to test the resistance of Wennong 14 to powdery mildew at both seedling and adult stages. Among the 52 Bgt isolates tested at the seedling stage, Wennong 14 was resistant to 43 and susceptible to 9 isolates. The virulence pattern of these Bgt isolates on Wennong 14 was similar to that of the known powdery mildew resistance gene Pm2, but the reactions of Wennong 14 to 11 Bgt isolates differed from those of Ulka/8*Cc carrying Pm2. Additionally, Wennong 14 was different from Tabasco carrying Pm46 in the reaction to three of 26 isolates examined. Wennong 14 was highly resistant to a mixture of Bgt isolates at the adult stage. Using the segregation populations of F2 and F2:3 developed from the cross of Wennong 14 × Han 4564, genetic analysis demonstrated that the resistance against Bgt isolate E09 in Wennong 14 was controlled by a single dominant gene, designated PmW14. Based on the results of molecular analysis, PmW14 was linked to markers Xcfd8, Xcfd81, and SCAR203, with genetic distances of 7.5, 1.8, and 7.7 cM, respectively. These markers were previously localized on wheat chromosome 5DS in the region of 5DS-1-0-0.63 and linked to gene Pm2, therefore, PmW14 was most likely located on this locus and to be either the same as or an allele of Pm2.