玉米抗倒伏相关性状QTL的关联和连锁分析

Dissecting the genetic architecture of lodging related traits by genome-wide association study and linkage analysis in maize

倒伏是影响玉米高产和机械化收获的重要因素,明确玉米抗倒伏相关性状的遗传基础,增强玉米品种抗倒伏能力,可为玉米高产宜机收育种提供理论依据。本研究以国内外收集的153份自交系为材料,利用6H90K SNP芯片检测的70,438个高质量SNP标记对地上第3节茎秆强度、株高、穗位高和穗位系数进行全基因组关联分析,分别检测到与茎秆强度、株高、穗位高和穗位系数相关位点5个、14个、16个和21个,单个关联位点最大效应值为13.24。同时以KA105/KB020的F_(5)群体为试验材料,采用QTL IciMapping V4.2软件的完备区间作图法进行QTL定位,检测到21个与抗倒伏相关的QTL,可解释表型变异3.86%~16.58%。结合关联分析和连锁分析结果发现,2个QTL区间与关联分析的候选区间重合。经过候选区段的基因功能注释和文献查阅,挖掘到GRMZM2G105391、GRMZM2G014119和GRMZM2G341410等与细胞壁生物合成、细胞分裂和细胞伸长的相关基因可供进一步分析。本研究结果为进一步解析玉米抗倒伏性状的遗传基础提供参考。

Lodging is one of the main factors affecting the grain yield and mechanized harvesting in maize.Dissecting the genetic basis of lodging related traits can provide a theoretical basis for high yield and mechanized harvest breeding of maize.In this study,genome-wide association study(GWAS)and linkage analysis were combined to identify the significant loci interrelated with lodging related traits using 153 inbred lines from China and abroad.We detected 5,14,16,and 21 SNPs significant SNPs related to stem strength,plant height,ear height,and ear height-to-plant height ratio,respectively.Among these significant SNPs,the maximum effect value of a single site was 13.24.Twenty-one QTLs related to lodging related traits were identified by linkage analysis,which explaining the phenotypic variations of 3.86%-16.58%in F_(5) population constructed by KA105 and KB020.Fur-ther,we noticed that two QTL intervals were coincided with the candidate intervals of association analysis.Finally,GRMZM2G105391,GRMZM2G014119,and GRMZM2G341410 candidate genes related to cell wall biosynthesis,cell division and elongation were predicted by functional annotation for these candidate regions.These results can provide a new reference for further analysis of the genetic basis of lodging resistance in maize.