Pyramiding two genes for leaf rust and powdery mildew resistance in common wheat

Abstract

Leaf rust, caused by Puccinia recondita f. sp. tritici, and powdery mildew, caused by Blumeria graminis f. sp. tritici, are the most prevalent of all of the wheat diseases in many regions of the world including Poland. These two diseases can cause serious epidemics in Poland. The aim of presented research was pyramiding of leaf rust and powdery mildew resistance genes in a one genotype. A leaf rust resistance gene Lr41, derived from Triticum tauschii (syn. Aegilops squarrosa) and powdery mildew resistance gene, derived from Dasypyrum villosum (syn. Haynaldia villosa), were successfully transferred into the polish winter wheat variety. A line KS90WGRC10 was used as the resistance source of Lr41 for leaf rust and the 6VS/6AL translocation line Yangmai 5 was used as the resistance source of Pm21 for powdery mildew. In foreground selection several molecular markers for Lr41 (Gdm35, Barc124, Gwm261, Gwm296 and Gwm210) and Pm21 (SCAR1250, SCAR1400 and NAU/xibao) were applied. After the first backcrosses (BC1F1), background selection was conducted using a set of 5 AFLP primer combinations. In addition, for the screening of the BC1F2 and BC1F3 population, selected lines were inoculated in the greenhouse at the three-leaf stage with a natural pathogen population of P. recondita and B. graminis. The marker-assisted selection and pathology test allowed us to obtain homozygous lines carrying two resistance genes to leaf rust and powdery mildew in winter wheat.