Refinement of four major QTL for oil content in Brassica napus by integration of genome resequencing and transcriptomics

Rapeseed (Brassica napus) supplies about half of the vegetable oil in China. Increasing oil production and searching for genes that control oil content in the crop are research goals. In our previous studies, four major QTL for oil content located on A08, A09, C03 and C06 in the KenC-8 × N53-2 (KN DH) mapping population were detected. The parental lines were resequenced to identify structural variations and candidate genes affecting oil content in these four major QTL regions. Insertion-deletion (InDel) markers were developed and used to narrow the regions. Differentially expressed genes located in the regions were investigated. GO and KEGG analysis showed that several genes were associated with lipid metabolism. Several transcription factors with higher expression in N53-2 than in KenC-8 were identified. These results shed light on the genetic control of oil content and may be helpful for the development of high-oil-content cultivars.