Important chromosomal regions for genetic control of powdery mildew resistance under control, drought, and saline conditions in barley (Hordeum vulgare L.)

Powdery mildew, caused by Blumeria graminis f. sp. hordei, is one of the most important fungal diseases in barley. In the current study 106, RIL lines derived from a cross between Badia and Kavir were utilized in order to identify and validate quantitative trait loci (QTLs) associated with the powdery mildew resistance at seedling and adult stages under control, drought, and saline conditions. First, the responses of the lines were evaluated at seedling stage, and in the following experiments, the responses of the adult lines to powdery mildew were assessed under control, drought, and saline conditions. A genetic map totaling 999.2 cM spans across 7 linkage groups. Our results demonstrated the importance of chromosome 2H in reducing the symptoms of the disease. qPm.SEVAD-7b and qPm.AUDPCAD-7 on chromosome 7H were involved in increasing the resistance against powdery mildew under drought condition. When the plant was exposed to saline stress, qPm.SEVAS-5 and qPm.SEVAS-3 explained a high percentage of disease resistance. The present study indicated that 135.8 to 136 and 125 to 136 cM from the distal end of short arm chromosome on chromosome 4H have very important roles in controlling the severity of the disease. Our results showed that GBM1164, CAAT4-A, GBM1450, and Scot4-E can be used in breeding programs to increase resistance to powdery mildew. This research can provide useful information to subsequent construction of fine mapping and marker-assisted selection breeding.