Identification of Molecular Markers Associated with Seed Dormancy in Micro-core Collections of Chinese Wheat and Landraces

Seed dormancy evaluated by germination index (GI) is often regarded as a main and pivotal component of observed genetic variation for pre-harvest sprouting (PHS). Improving seed dormancy can decrease or avoid PHS damage to wheat before harvest. However, it is difficult to accurately evaluate seed dormancy under field conditions. In this study, 4 simple sequence repeat markers (Xbarc57, Xbarc294, Xbarc310, and Xbarc321) on the short arm of chromosome 3A and a gene-based marker (Vp1-b2) on 3BL were used for genotyping 138 micro-core collections of Chinese wheat and landraces. Rich alleles were detected using these markers, and most of them were significantly correlated with GI value. A significant association between the 5 markers and seed dormancy was found according to General Linear Model. Vp1-b2 and Xbarc294 had larger effects on seed dormancy than other markers, which accounted for 65.8% and 61.2% of phenotypic variation, respectively. Combination of the 5 marker gave the largest estimation of GI variation in the 138 wheat genotypes (95.9%), followed by marker combination Vp1-b2/Xbarc294 (89.1%), and marker combination Vp1-b2/Xbarc321 had the smallest effect (79.4%). This result indicated that seed dormancy of tested genotypes was mainly associated with 2 loci on 3AS and 3BL.