QTL mapping and candidate gene identification of seed glucosinolate content in Brassica napus

Abstract

Abstract [Objective] The study aims to discover the genetic loci and candidate genes of seed glucosinolate content in Brassica napus, and lay a foundation for the cloning of genes involved in glucosinolate metabolism and improving the breeding of B. napus. [Methods] Using KN DH populations from four different environments as materials, the QTL mapping of seed glucosinolate content and the candidate genes were analyzed. [Results] (1) The variation coefficient of seed glucosinolate content in B. napus was high and stable, which followed the genetic characteristics of quantitative traits. (2) Seven consistent QTLs, including cqGC.A9-5, cqGC.A9-7, cqGC.A9-9, cqGC.C2-9, cqGC.C2-10, cqGC.C9-5 and cqGC.C9-6, were environmentally stable QTLs, of which cqGC.A9-5, cqGC.C2-10, and cqGC.C9-5 were major QTLs. (3) Three candidate genes, including BnaA09g05480D, BnaC09g05620D, and BnaC09g05810D, were identified in the interval of the major QTL cqGC.A9-5 and cqGC.C9-5. Based on their annotation, these candidate genes were involved in the biosynthetic pathway of glucosinolates (the biosynthesis of IAOx and 3-alkyl malic acid) and transport and distribution of glucosinolates. [Conclusion] Seed glucosinolate content in B. napus was quantitative trait. Three major QTLs for seed glucosinolate content were identified, which might be involved in the synthesis of intermediate products and the transport and distribution of glucosinolates.

Keywords

• brassica napus l.
• seed glucosinolate content
• qtl mapping
• candidate gene