Molecular mapping of two quantitative trait loci for adult-plant resistance to powdery mildew in common wheat (Triticum aestivum L.)

Powdery mildew is one of the major wheat diseases in regions with maritime or semi-continental climate and can strongly affect grain yield. Breeding wheat varieties with quantitative resistance to powdery mildew would be relatively more durable and promising than varieties with only major resistance genes (Pm genes). The chief aim of the present study is to map the quantitative trait loci (QTLs) for adult plant resistance (APR) to powdery mildew. A population of 176 recombinant inbred lines was developed from a cross of “Shannong 0431 × Lumai 21” (SN0431 × LM21) and evaluated for disease severity of powdery mildew under two cropping seasons. Two major QTLs (QPm.sdau-2A and QPm.sdau-2B) for APR to powdery mildew were mapped on chromosomes 2A and 2B, which were contributed by LM21 and SN0431. The molecular markers associated with the QTLs will be useful for selecting partial and potentially durable resistance genes against powdery mildew.