Association mapping of salt tolerance traits at germination stage of rapeseed (Brassica napus L.)

Soil salinization has a major effect on crop yield. Seed germination is a crucial prerequisite for the successful cultivation of rapeseed in saline soils. Limited information is available about rapeseed salt tolerance at germination stage. Here, we carried out an association mapping of salt tolerance QTLs at seed germination stage. We evaluated salt tolerance of 214 rapeseed inbred lines at germination stage, and the 60 K Brassica Infinium® SNP array was used to genotype the association panel. Finally, a total of 110 single nucleotide polymorphisms (SNPs) were associated with three salt tolerance indices and these SNPs were integrated into 44 QTLs. In addition, 56 possible candidate genes were located in or near the genomic region where the above QTLs were mapped. Thus, our results provide valuable information for understanding the genetic control of rapeseed salt tolerance at germination stage and may facilitate marker-based breeding for rapeseed salt tolerance.