Identification of Candidate Genes for Seed Glucosinolate Content Using Association Mapping in Brassica napus L.

Abstract

Rapeseed contains glucosinolates, a toxic group of sulfur-containing glucosides, which play critical roles in defense against herbivores and microbes. However, the presence of glucosinolates in rapeseed reduces the value of the meal as feed for livestock. We performed association mapping of seed glucosinolate (GS) content using the 60K Brassica Infinium single nucleotide polymorphism (SNP) array in 520 oilseed rape accessions. A total of 11 peak SNPs significantly associated with GS content were detected in growing seasons of 2013 and 2014 and were located on B. napus chromosomes A08, A09, C03, and C09, respectively. Two associated regions of GS content covered by these markers were further verified, and three B. napus homologous genes involved in the biosynthesis and accumulation of GS were identified. These genes were multigene family members and were distributed on different chromosomes. Moreover, two genes (BnGRT2 and BnMYB28) associated with GS content were validated by the qRT-PCR analysis of their expression profiles. The further identification and functionalization of these genes will provide useful insight into the mechanism underlying GS biosynthesis and allocation in B. napus, and the associated SNPs markers could be helpful for molecular maker-assisted breeding for low seed GS in B. napus.

A combination of genome-wide association and transcriptome analysis reveals candidate genes controlling harvest index-related traits in Brassica napus

“…Based on a previous study, the 520 B. napus accessions were divided into two subgroups (P1 and P2)11 (Supplementary Table S1). We estimated the relative kinships12, and found 68.87% of the kinship coefficients ranged from 0 to 0.05, with 55.32% of pairwise kinship coefficients being 0 (Fig.…”

“…The SNP data were analyzed by Illumina BeadStudio genotyping software, as previously described11. SNPs with minor allele frequencies (MAFs) of <0.05, or lacking a call higher than 0.9 were excluded from analysis.…”

“…The population structure (Q) was inferred using STRUCTURE 2.3.4, as we previously reported11. The relative kinship matrix (K) and principal component (PC) of the natural population were calculated using TASSEL 5.2.112.…”

Genome-Wide Survey of Flavonoid Biosynthesis Genes and Gene Expression Analysis between Black- and Yellow-Seeded Brassica napus

“…B 3 and Y 3 were represent two near isogenic lines of black- and yellow-seeded B . napus , selected from the successive backcross of the sixth generation with parent ZS11 and recurrent parent 06E241 (Qu et al, 2015). The plants were grown under normal field conditions at Chongqing Rapeseed Technology Research Center (CRTRC) in 2014.…”

Fire and Brimstone: Molecular Interactions between Sulfur and Glucosinolate Biosynthesis in Model and Crop Brassicaceae

“…A further 25 mQTL for seed aliphatic GSLs were identified on the A genome (Feng et al, 2012), of which only four are thought to have been identified previously in B. juncea (AB genome) (Ramchiary et al, 2007; Bisht et al, 2009). Very recently, biparental and association mapping studies in B. juncea (Rout et al, 2015) and B. napus (Qu et al, 2015) identified additional QTLs associated with GSL compositional variation and seed GSL accumulation.…”