Identification of QTLs involved in pod-shatter resistance in Brassica napus L.

Seed loss caused by pod-shatter during harvesting is one of the main problems in rapeseed production worldwide. Quantitative trait loci (QTLs) for pod-shatter based on genetic mapping would help breeders develop cultivars resistant to pod-shatter. In this study, we constructed a genetic map of Brassica napus containing 107 simple sequence repeat (SSR) markers and 68 sequence-related amplified polymorphism (SRAP) markers using a doubled-haploid (DH) population of 276 lines derived from the cross H155 × Qva. This map covered 1382.8 cM with an average marker interval of 7.9 cM. In total, 13 QTLs for pod-shatter resistance were identified in this DH population at two experimental sites (in Wuhan and Zhengzhou); three of the QTLs were present at both locations. At Zhengzhou, nine QTLs, identified in linkage groups A1, A7, A8, C5, and C8, together explained 49.0% of the phenotypic variation. At Wuhan, four QTLs were mapped on the A1, A4, A7, and C8 linkage groups. These QTLs explained 38.6% of the phenotypic variation. These results may serve as a valuable basis for further molecular dissection of pod-shatter resistance in B. napus, and for development of the markers related to QTLs that may be useful for marker-assisted selection of pod-shatter resistant cultivars.