甜玉米种质资源种子性状全基因组关联分析

Genome-wide association study of grain traits of sweet maize germplasm resources

粒长、粒宽、粒厚、百粒质量是影响玉米籽粒产量的重要性状,本研究主要统计分析了100份甜玉米种质资源的粒长、粒宽、粒厚和百粒质量等4个种子性状,并利用37297个单核苷酸多态性(SNP)标记位点关联分析了控制甜玉米种子性状的重要位点。结果表明,100份甜玉米种质资源种子性状具有丰富的遗传多样性,性状变异幅度比较大,其中粒长为4.65~10.43 mm,粒宽为5.13~9.42 mm,粒厚为2.04~7.50 mm,百粒质量为4.51~20.09 g;表型变异分析发现,百粒质量的变异系数最大,为32.60%,粒宽的变异系数最小,为10.61%,且4个籽粒性状的频率分布曲线基本符合正态分布。相关性分析结果表明,粒长、粒宽、粒厚与百粒质量呈极显著正相关,粒长与粒厚呈极显著负相关。全基因组关联分析共检测到控制4个种子性状的75个SNP标记位点,其中有17个SNP标记位点与粒长性状有关,24个SNP标记位点与粒宽性状有关,11个SNP标记位点与粒厚性状有关,23个SNP标记位点与百粒质量性状有关。

The grain length,grain width,grain thickness and hundred-grain weight are important traits affecting the yield of maize.Four characters of seeds such as grain length,grain width,grain thickness and hundred-grain weight of 100 germplasm resources of sweet maize were summarized and analyzed in this study,and 37297 single nucleotide polymorphism(SNP)loci were used to make correlation analysis on the important loci controlling the grain traits of sweet maize.The results showed that the grain traits of 100 germplasm resources of sweet maize had abundant genetic diversity with a relatively large variation range.The grain length was 4.65-10.43 mm,the grain width was 5.13-9.42 mm,the grain thickness was 2.04-7.50 mm and the hundred-grain weight was 4.51-20.09 g.Analysis on the phenotypic variation revealed that,the variable coefficient of the hundred-grain weight was the highest,with a value of 32.60%,and the variable coefficient of the grain width was the lowest,with a value of 10.61%.The distribution curves of frequencies of four grain traits were basically conformed to normal distribution.Results of correlation analysis showed that,the grain length,grain width and grain thickness were positively correlated with the hundred-grain weight very significantly,the grain length was negatively correlated with the grain thickness very significantly.A total of 75 SNP loci controlling the traits of four seeds were detected through genome-wide association study.Among the 75 SNP loci,17 SNP loci were related with the grain length,24 SNP loci were related with the grain width,11 SNP loci were related with the grain thickness and 23 SNP loci were related with the hundred-grain weight.