玉米主要株型性状与产量的全基因组关联分析

Genome-Wide Association Analysis of Major Plant Architecture Traits and Yield in Maize

为了深入剖析玉米的株型性状和产量性状的遗传基础及其相关关系,本研究以204份玉米自交系作为关联群体,利用分布于玉米全基因组上的558529个单核苷酸多态性标记(SNPs)对5个相关性状进行全基因组关联分析。结果表明,供试自交系各性状基本呈正态分布,且各性状间存在丰富的变异,变异系数在9.00%~50.00%之间;通过相关性分析和热图层次聚类分析株型和产量相关性状间彼此紧密关联;且由主成分分析筛选出总体方差累计贡献率达到71.667%的主成分2个;以P≤1×10^-5为显著阙值,利用Q+K模型对供试材料的5个相关性状进行全基因组关联分析,在株高、穗位高和单穗重间共检测到13个显著的SNP位点,分别分布于玉米的第3、第5、第6、第7号染色体上,而在总叶片数和穗上叶数间未检测到显著的SNP位点;在显著SNP上下游各50 kb范围共搜索到39个相关候选基因,其中有注释的基因12个,并对株高与穗位高最佳候选基因进行了预测。本研究通过对玉米株型及产量相关性状进行全基因组关联分析,为后期基因功能的验证与新功能的开发奠定了良好的基础。

In order to deeply analyze the genetic basis of plant architecture and yield,and to explore the relationship between them.In this study,genome-wide association analysis were performed associating 5 related traits of 204 maize inbred to 558529 single nucleotide polymorphism markers(SNPs)distributed on the whole maize genome using Q+K model.The results showed that the traits were basically normal distribution,and there were abundant variations among the traits,with the coefficient range of 9.00%-50.00%.Through correlation analysis and heat map hierarchical cluster analysis,it can be seen that plant architecture and yield-related traits are closely related to each other,and traits are interrelated and coordinated with each other.The principal component analysis shows that 2 principal components with a cumulative contribution rate of 71.667%of population variance have been screened out,which can represent the vast majority of information of 5 related traits.With P≤1×10^-5 as the significant threshold,a total of 13 significant SNP loci were detected among plant height,ear height and ear weight,which were distributed on chromosomes 3,5,6 and 7,while no significant SNP loci were detected between the leaf number and leaf number above ear.Through the search of candidate genes in the range of 50 kb in the upstream and downstream of SNP,a total of 39 related genes were found,including 12 annotated genes,and the best candidate genes for plant height and panicle height were predicted.In this study,the genome-wide association analysis of plant type and yield traits in maize can lay a good foundation for the verification and the development of gene functions in the future.