IDENTIFICATION OF GENOMIC REGIONS ASSOCIATED WITH LEAF BLIGHT RESISTANCE IN BARLEY

Leaf blight or Spot blotch, caused by Bipolaris sorokiniana, is a serious foliar disease of barley (Hordeum vulgare L.) which may cause a significant yield loss of more than 30% at adult plant stage. The Quantitative Trait Loci (QTLs) studies in barley have concluded debatable complex inheritance of leaf blight resistance due to different genetic background of mapping populations with very few reports coming from India. An integrated approach is recommended with host resistance as a major component to identify QTLs and specific markers targeted for genomic regions involved in leaf blight resistance in Indian barley lines. Leaf blight resistant (DWR49) and susceptible (RD 2503) lines were crossed to investigate inheritance of resistance and to identify QTLs associated with resistance. 283 SSR and STS primers specific to all the seven chromosomes were used to screen the parental lines, of which 50 showed polymorphism over resistant and susceptible bulks and used for genotyping of 142 RILs (Recombinant Inbreed Lines) of the cross DWR49 x RD2503. Eleven molecular markers (Bmac 213, ABG 058, Bmag 125, Hv5s, Gbm1208, GBM1444, GBM1506, GMS1, GBM5012, Ebmac827, and Bmag369) specific to chromosome 1H, 2H, 3H, 5H, 6H and 7H were found closely linked during chi-square analysis. The findings may be useful in developing a marker-assisted selection strategy for leaf blight resistance in barley.