Mapping of QTL for Pre-Harvest Sprouting Resistance and Seed Dormancy in a Doubled Haploid Population

Pre-harvest sprouting (PHS) of wheat reduces grain yield and has deleterious effects on wheat flour quality. PHS resistance is strongly associated with grain color and seed dormancy. Resistance to PHS is a priority of wheat breeding program. We have studied a population of 122 Doubled Haploid (DH) lines from the cross between two cultivars, ‘Keumkang’ and ‘Olgeuru’, in order to detect QTLs correlated with PHS resistance. PHS was evaluated using mist spray in the humid chamber (PHS-MS), and the germination index (GI) was determined for two years. The variety ‘Keumkang’ has white grains and higher percentage of PHS rate (30.2%), while ‘Olgeuru’ has red grains and lower PHS rate (2.8%). There was significant difference in grain color according to the GI. PHS-MS was positively correlated with GI (r = 0.732, P < 0.001). Two molecular markers, Xbarc12 and Xgwm3, were found correlated with PHS resistance and GI. These markers were mapped on chromosomes 3A and 3D with LOD scores of 4.95 and 4.02, respectively. Xbarc12 explained the highest amount of phenotypic variation (R2) which is 11.99% in GI and 27.25% in PHS. Xgwm3 explained 9.10% of phenotypic variation in GI. The respective value of PHS-MS and GI in Korean wheat cultivars ranged from 1.37% to 86.75% and from 0.03 to 0.73. This study provides useful information for marker-assisted wheat breeding for PHS resistance improvement in Korea.