大豆7S球蛋白α'亚基缺失新种质中黄608的分子鉴定

大豆7S球蛋白α'亚基含量与大豆的营养品质和加工特性关系密切。本研究利用聚丙烯酰胺凝胶电泳(SDS-PAGE)和免疫印迹法(Western blot)从中品661的EMS突变库中筛选出α'亚基缺失突变体中黄608。利用中黄608与登科1号创建了一个由210个个体组成的F2分离群体。遗传分析表明,α'亚基缺失由1对隐性单基因控制。利用连锁分析方法将该基因定位于第10染色体标记SSR10-1489与SSR10-1612之间,其中,包括控制α'亚基合成基因Cgy-1(Glyma.10G246300),序列分析发现,中黄608在Cgy-1第1外显子第84个碱基发生单碱基突变(G84→A84),导致氨基酸翻译提前终止。根据新发现的变异位点开发了共显性分子标记,并检测F2个体基因型,结果表明, Cgy-1基因型与α'亚基表型共分离。本研究不仅为大豆优质育种提供了新材料,同时也为分子育种提供了技术支持。

Molecular identification of a new soybean germplasm Zhonghuang 608 lacking of 7S globulin alpha' subunit

The content of alpha' subunit of 7S globulin has an important effect on the nutritional quality and processing characteristics in soybean. In this study, using polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting, Zhonghuang 608 (ZH608), an α' subunit deletion mutant, was identified from the Zhongpin 661 (ZP661) EMS mutant library. Zhonghuang 608 was crossed to the soybean variety Dengke 1, and self-pollinated to establish an F₂ segregating population composed of 210 individuals. Genetic analysis showed that the alpha' subunit deletion trait in ZH608 was controlled by a single recessive nuclear gene. By linkage analysis we mapped the locus between SSR10-1489 and SSR10-1612 on chromosome 10. Coincidentally, in the mapping region Cgy-1 (Glyma.10G246300) was annotated as an alpha' subunit synthesis-related gene according to the Williams 82 reference genome. Further sequence analysis showed that the mutant had a single base change (G ⁸⁴ to A ⁸⁴) in the first exon of Cgy-1, which resulted in the premature termination of the amino acid sequence. Based on the newly discovered SNP mutation, a co-dominant molecular marker was developed, and used to detect the genotypes of those F₂ individuals. The results indicated that the Cgy-1 genotype cosegregated with the alpha' subunit phenotype in the F₂ segregating population of Zh608 and Dengke 1. This study not only provides new materials for quality improvement, but also offers technical support for molecular breeding in soybean.