CONSTRUCTION OF GENETIC LINKAGE MAP AND QTL ANALYSIS OF NET BLOTCH RESISTANCE IN BARLEY

Abstract

Net blotch, caused by Pyrenophora teres f. teres, is one of the most devastating diseases causing significant losses in barley yield and quality. In the present investigation, two barley verities “AT4” (net blotch resistant) and “Femina” (net blotch susceptible) were used to develop a segregating F2 population. Linkage analysis and map construction were performed using Map Manager. The constructed genetic linkage map consisted of 85 markers including 45 AFLP , 11 SSR, 6 CAPS, 5 SCoT, 3 STS and 6 NBL. Linkage groups were assigned to individual barley chromosomes using the published map locations of the SSR markers as reference point. The produced map showed 7 linkage groups with 85 markers covered a total length of 1644.8 cM. The average length of linkage groups ranged from 77.7 to 739.4. Single point analysis was used to identify the genomic regions associated with net blotch resistance in barley. A total of 14 QTL with a significance ranging from 0.01% to 5% were identified on 4 linkage groups (2, 4, 5 and 6). The most significant QTL was found on chromosome 6H. This QTL presents a promising opportunity for the strategic improvement of barley resistance to net blotch using marker assisted selection.