Iddentification of QTLs for grain weight in barley doubled haploid population

To identify the QTLs affecting grain weight and yield, 148 doubled-haploid (DH) population derived from a cross between Clipper (high yield) and Sahara3771 (low yield) were screened under controlled conditions. The experiment was conducted in CRD with 3 replications. The new 30 ISSR marker loci were added to a backbone of 466 loci on the Clipper × Sahara DH linkage map. The map spanned 1460 centimorgans (cM) and had a mean density of 2 loci per 3 cM. The QTL analysis led to identification of 5 QTLs on 2H, 4H, 5H and 6H chromosomes for grain yield. These QTLs could explain 57% of the total phenotypic variation, and the QTL on chromosome 2H (ksuF2-mwg892) with 20% had the largest effect. For grain weight, 3 QTLs were identified, and the QTL on 2H could explain 69% of total phenotypic variation. The identification of QTLs with large effects on grain weight and yield illustrates the usefulness of molecular markers in gene mapping and suggest that marker-assisted selection will be feasible in the near future in barley breeding programs.