Abstract

Seed dormancy, a main factor contributing to preharvest sprouting (PHS) tolerance, is an adaptive trait largely affected by environmental conditions, such as temperature and moisture, during seed development and after ripening. PHS reduces the end-use of wheat by declining grain quality, which leads to further economic losses. The wheat cultivar ‘Chinese Spring’ (CS) has ph and kr genes, and was always used as bridge parent to cross with related species in order to transfer good genes from other species. The wheat cultivar CS has moderate seed dormancy level. However, it was widely used to be crossed with stronger dormant varieties to characterize the dormant genes of strong dormancy varieties, the dormant traits of CS itself have not been indicated enough. Germination index (GI) and Germination percent (GP) of CS and its 36 ditelosomics were tested. It suggested that 3AS, 4AS, 6AS, 2BS and 1DS carry major gene(s) associated with wheat seed dormancy. Furthermore, CS and its five corresponding ditelosomics were crossed with an undormancy wheat accession YY2. The lines obtained from DT3AL, DT4AL, DT6AL and DT2BL showed statistically (at 5% level) higher in both GP and GI than that from CS × YY2 line. It indicated that 3AS, 4AS, 6AS and 2BS in CS carry major dormancy gene(s) relative to YY2. A QTL map of GP and GI was carried out at the different region on the short arm of chromosome 2B, which ranged the order as Xgwm510, Xgwm210, Xgwm50, QTL_GI, QTL_GE and QTL_GP, and the genetic distance were 28.5, 2.6, 25.7, 16.4 and 13.7 cM, respectively.

Key words: Wheat, Ditelosomics analyses, seeds dormancy, quantitative trait locus (QTL) mapping.