玉米穗粗性状的全基因组关联分析及QTL元分析

Genome-wide association study and Meta-QTL analysis of ear diameter trait in maize

玉米(Zea mays)是全世界总产量最高的粮食作物,穗粗是玉米单株产量的重要指标。利用Farm CPU软件对292份玉米自交系进行全基因组关联分析(GWAS),筛选到28个显著性单核苷酸多态性(SNP)位点。借助IBM2 2008 Neighbors高密度图谱整合了2007~2015年文献发表的105个玉米穗粗性状的数量性状基因座(QTL),采用元分析的方法,确定了10个与穗粗相关的"一致性"QTL(Meta-QTL)。通过查询各年各点最显著的SNP位点,以及位于Meta-QTL内的显著性SNP位点,获得了9个玉米穗粗的候选基因,分别位于玉米染色体区段bin 1.10、3.09、4.08、5.05、6.07、8.03、9.05、10.04。全基因组关联分析和Meta-QTL筛选的穗粗候选基因可以为玉米分子标记辅助育种和基因克隆提供有用的信息。本研究对玉米穗粗性状的遗传改良及高产稳产育种提供参考。

Maize（Zea mays L.） is a kind of food crop with the highest total yield in the world,and ear diameter is an important index of yield in maize.In this study,genome-wide association study（GWAS） of ear diameters in 292 inbred lines was carried out with Farm CPU software,and 28 significant SNP（single-nucleotide polymorphism） loci were identified in maize.With the help of IBM2 2008 Neighbors high density map,105 QTLs（quantitative trait loci） of maize ear diameter characters,which were published from 2007 to 2015,were integrated with the method of meta-analysis.Results show that the ear diameter was related to 10 Meta-QTL.By searching the most significant SNP sites,and the significant SNPs which were located in Meta-QTL,9 candidate genes related to ear diameter of maize were obtained,and these genes are located in maize chromosome bins 1.10,3.09,4.08,5.05,6.07,8.03,9.05,10.04,respectively.Candidate genes identified by genome-wide association analysis and Meta-QTL can provide useful information for molecular marker-assisted breeding and gene cloning in maize.This study has guiding significances for the genetic improvement of ear diameter and breeding of high and table yield in maize.