QTLs Detection for Low-Temperature Germination in Rapeseed by QTL-seq and Linkage Mapping Approach
Abstract Rapeseed is a major oil crop in the world, which is easily affected by low-temperature stress. Low-temperature delays seed germination and increases seedling mortality that adversely affects rapeseed growth and production. To understand the genetic mechanisms of seed germination under low-temperature in rapeseed, we crossed a tolerant cultivar with a susceptible genotype to develop a mapping population of 574 F2 progenies. Two quantitative trait loci (QTLs) for low-temperature germination (LTG) were detected on chromosome A09 (named qLTGA9-1) and C01 (named qLTGC1-1) using QTL-seq method, and confirmed via linkage analysis in the mapping population. qLTGA9-1 was mapped to a 341.86-kb interval between SSR markers Nys9A212 and Nys9A215. In this region, 69 genes including six specific genes with moderate or high effect function variant were identified based on Ningyou7 genome sequence. qLTGC1-1 was mapped a 1.31-Mb interval between SSR markers Nys1C96 and Nys1C117. In this region, 133 genes including five specific genes with moderate effect function variant were identified based on Ningyou7 genome sequence. These specific genes within the two QTLs could be targets in rapeseed breeding programs and further studies for cold tolerance.