Association of candidate genes for fatty acid content in soybean by temperature-switch PCR (TSP) genotyping

Abstract The development of molecular markers is essential for improvement of soybean cultivars with modified fatty acid content. The objective of this study was to identify and validate SNP markers in candidate genes for fatty acid content in soybean. Six candidate genes (ARAF, PDAT, ABI3, FAD2-1b, FAD3B, and FAD3C) were selected. Alignment of gene sequences identified 25 SNPs and 3 INDELs. TSP primers were used to identify SNP alleles. 259 recombinant inbred lines (RILs) (FA22 / CD219) and 185 F2 progenies (A29 / Tucunaré) were tested for association of SNPs. An SNP for FAD3B was associated with variation in content of linoleic acid (R2 = 5.84%) and linolenic acid (R2 = 6.79%). In FAD3C, an SNP was associated with linoleic and linolenic acids (R2 of 9.21% and 18.51%, respectively). The ABI3 gene was associated with palmitic acid, with R2 = 5.41%. The SNP markers identified will be used in assisted selection for improvement of fatty acid content.

摘要 开发分子标记对于培育脂肪酸组分改良的大豆品种至关重要。本研究旨在鉴定并验证大豆脂肪酸含量相关候选基因内的单核苷酸多态性（Single Nucleotide Polymorphism, SNP）标记。本研究共筛选得到6个候选基因：ARAF、PDAT、ABI3、FAD2-1b、FAD3B及FAD3C。对上述基因的序列进行比对分析后，共鉴定出25个单核苷酸多态性位点与3个插入缺失（Insertion-Deletion, INDEL）多态性位点。采用TSP引物对SNP等位基因进行分型鉴定。以259份重组自交系（Recombinant Inbred Line, RIL）群体（FA22/CD219）及185份F₂后代群体（A29/Tucunaré）为材料，开展SNP位点与脂肪酸含量的关联分析。结果显示，FAD3B基因内的1个SNP位点与亚油酸（R²=5.84%）及亚麻酸（R²=6.79%）的含量变异显著相关；FAD3C基因内的1个SNP位点与亚油酸、亚麻酸含量变异相关，对应决定系数分别为9.21%和18.51%；ABI3基因内的1个SNP位点与棕榈酸含量变异相关，决定系数为5.41%。本研究鉴定得到的SNP标记可用于脂肪酸组分改良的分子标记辅助选择育种。