大豆贮藏蛋白主要成分是7S和11S球蛋白,大豆贮藏蛋白组分及其亚基组成决定了蛋白质的品质和加工特性。本研究选用134对细胞核SSR标记,对166份栽培大豆微核心种质进行基因分型,运用一般线性回归(general linear model,GLM)和复合线性回归(mixed linear model,MLM)方法进行标记与性状的关联分析,定位大豆蛋白亚基的相关基因。结果表明,2年均检测到的且与蛋白亚基相关联的SSR位点有14个,以MLM方法检测到5个SSR位点(Sat_062、Satt583、Satt291、Satt234和Satt595)与蛋白亚基相关联;7S组分各亚基变异程度较大,是引起11S/7S变异的主要原因;表型变异较大的亚基可能因为相关基因进化中发生重组较多,LD衰减距离较小,导致检测到较少的相关位点。本研究结果对蛋白亚基相关性状的标记辅助选择育种有重要的利用价值。
Glycinin (11S) and β-conglycinin (7S) are major components of seed storage protein in soybean, which play important roles in the functionality of seed protein. In the present study, association mapping was used to map the QTLs (quantitative trait loci) for glycinin (1 IS) and ~-conglycinin (7S) fractions. One hundred and sixty-six accessions from Chinese soybean minicore collection were genotyped with 134 selected simple-sequence repeat (SSR) markers. The storage protein of each accession was separated by SDS-PAGE method, and gels were scanned for individual subunits of 11S and 7S by ImageQuant TL software. The association analysis between SSR loci and protein subunit components was performed with TASSEL GLM (general linear model) and MLM (mixed linear model) programs. The results showed that, both in 2008 and 2010, fourteen SSR loci associated with the protein subunit components were screened out by GLM program, and five SSR (Satt234, Satt595, Sat_062, Satt583, and Satt291) loci by MLM program, respectively. The high variation of 7S subunits was the main reason that caused 11S/7S ratio variance. Fewer loci were detected to be associated with the protein subunits whose phenotypic variations were higher, which might be due to the more recombination incidents during the evolution of the related genes. Therefore, the LD decay distances of these genes were short, some QTLs could not be detected with limited SSR markers. The results of this study are meaningful for the marker assisted selection breeding of soybean varieties with higher protein quality.