大豆低聚糖优异种质鉴定及GWAS分析

Identification and GWAS Analysis of Soybean Oligosaccharide Germplasm

大豆中含有丰富的营养物质和活性物质,其中低聚糖有许多对人体健康有益的功能,大范围的鉴定评价并筛选大豆低聚糖特异种质具有重要的育种意义。本研究利用高效液相色谱法(HPLC,high performance liquid chromatography),测量了包含264份大豆材料的自然群体的蔗糖含量、棉子糖含量、水苏糖含量以及总低聚糖含量。结果表明3种低聚糖中蔗糖占总低聚糖的比例最高,棉子糖占比最低,海南三亚和江苏南京两个环境下大豆的总低聚糖含量范围分别为6.18%~11.46%和4.19%~13.80%,共筛选出不同环境下表现稳定的10份大豆低聚糖特异种质。结合大豆自然群体的低聚糖含量表型数据和基因型数据进行了全基因组关联分析,在不同环境下分别鉴定到与低聚糖显著关联的SNPs,并挖掘目的性状候选基因。本研究为特用大豆品种选育提供了材料支撑,为发掘大豆低聚糖候选基因和开发分子标记提供了较好的基础。

Soybean is rich in nutrients and active substances.Oligosaccharides are beneficial functional components for human health,and identification of soybean oligosaccharide specific germplasms is of great practical significance.In this study,the content of oligosaccharides,including sucrose,raffinose,stachyose and total oligosaccharide,were quantified by high performance liquid chromatography(HPLC)method in a population of 264 soybean genotypes that were cultivated at two environments.It was shown that among the three oligosaccharides,sucrose accounts for the highest proportion of total oligosaccharides,and raffinose accounts for the lowest proportion.The total oligosaccharide content in Sanya city of Hainan province and Nanjing city of Jiangsu province ranged from 6.18%-11.46%and 4.19%-13.80%,respectively.Ten oligosaccharide specific genotypes with stable performance at different environments were obtained.Genome-wide association study(GWAS)was carried out by combining phenotypic and genotypic data of oligosaccharide content in natural soybean population.SNPs significantly associated with oligosaccharides content were identified and candidate genes were considered to be related with oligosaccharide/sucrose.Collectively,this study provided germplasm resources applicable for the selection and breeding of special soybean varieties,and also provided foundation for further exploring oligosaccharide candidate genes and developing their molecular markers in soybean.