Abstract:

A powdery mildew resistance gene in a BC₃F₂ population, derived from a cross made between an amphidiploid of Triticum durum Desf.-Aegilops caudata L. and T. aestivum L. cv. Laizhou 953, was identified. Genetic analysis of resistance to powdery mildew in BC₃F₂ population and derived BC₃F₃ families indicated a single dominant gene controlled the resistance. By bulk segregation analysis, two microsatellite markers, Xgwm311 and Xgwm382, were identified to be closely linked to the resistance gene with genetic distance of 5.9 cM and 4.9 cM, respectively. DNA from T. durum accession DR147, Ae. caudata acc. Ae14, and recurrent parent wheat (Triticum aestivum L.) cv. Laizhou 953 were amplified with primer pairs WMS311 and WMS382, the specific bands related to the resistance gene were only present in T. durum acc. DR147. Results showed that the resistance gene originated in T. durum acc. DR147. Based on the location of the linked microsatellite markers, the resistance gene was located on the telomeric region of chromosome 2AL in wheat. Temporarily, the resistance gene was designated as PmDR147. The relation of this gene and Pm4 was discussed.

Key words: resistance gene, microsatellite, molecular tagging, powdery mildew, durum wheat