甘蓝型油菜种子硫苷含量全基因组关联分析

Genome-wide Association Study of Seed Glucosinolate Content in Brassica napus

【目的】挖掘与种子硫苷含量显著关联的SNP位点及候选基因,有助于油菜品质改良和培育高品质油菜品种。【方法】以300份甘蓝型油菜自交系为材料,考察了江西农业大学试验地和江西省红壤及种质资源研究所试验地2种环境下种子硫苷含量,采用前期开发的201817个SNP(singlenucleotidepolymorphism,SNP)标记对油菜种子硫苷含量进行全基因组关联分析(genome-wide association study,GWAS),搜寻显著位点两侧100 kb范围内的候选基因并进行功能注释。【结果】300份甘蓝型油菜种子硫苷含量在两地均表现出表型差异;基于一般线性模型和混合线性模型检测到209个硫苷含量显著关联SNP位点,其中两地两种方法重复检测到41个SNP位点,分别在A05(1个)、A09(36个)、C09(4个)3条染色体上。候选基因功能注释结果显示,有8个候选基因参与硫苷生物合成途径(GO:0019761),包含调控硫苷合成相关基因MYB28(BnaC09g05290D、BnaC09g05300D)、MYB34(BnaA09g05480D)和编码硫苷转运蛋白2相关基因(BnaA09g06180D、BnaA09g06190D)。【结论】通过两种方法在两地检测到多个与硫苷显著关联的SNP位点,并在显著性位点附近挖掘到相关候选基因,研究结果有助于解析甘蓝型油菜硫苷含量的遗传变异,为低硫苷含量油菜新品种的遗传改良提供基础。

【Objective】To explore SNPs and candidate genes significantly associated with seed glucosinolate content in rapeseed is helpful to improving rapeseed quality and cultivating high quality rapeseed varieties.【Method】Total 300 oilseed rapeseed inbred lines grew in the experimental field of Jiangxi Agricultural University(JXAU)and Jiangxi Institute of Red Soil and Germplasm Resources(JXIRS),and the seed glucosinolate content(SGC)was analyzed after harvested.A total of 201817 SNPs developed by SLAF-seq in all populations were used for genome-wide association with study(GWAS)of SGC.The 100 kb flanking regions on either side of significantly associated SNPs were used to identify candidate genes,and to perform functional annotations of these genes.【Result】The SGC of these populations showed phenotypic variations under two environments.Based on the general linear model(GLM)the mixed linear model(MLM),209 SNPs were detected to have significant association with SGC,and 41 SNPs on A05(1),A09(36)and C09(4)were detected by GLM and MLM under JXAU and JXIRS.The functional annotation of candidate genes showed that eight candidate genes participated in the glucosinolate biosynthetic process(GO:0019761),including regulating the glucosinolate synthesis related genes MYB28(BnaC09g05290D and BnaC09g05300D),MYB34(BnaA09g05480D),and the glucosinolate transporter 2 related genes(BnaA09g06180D and BnaA09g06190D).【Conclusion】The SNPs significantly associated with SGC were detected under two environments by GLM and MLM,and the candidate genes were mined at the flanking of SNPs,which is conducive to resolving the genetic variation of SGC and providing a basis for the genetic improvement of new rapeseed varieties with low SGC.