玉米穗三叶叶长和叶面积的QTL定位

Identification of QTLs for Length and Area of Three Leaves Near the Ear in Maize

玉米叶长和叶面积是重要的农艺性状,为解析玉米穗三叶叶长和叶面积的遗传机制,以郑58和D863F及其杂交构建的241个RIL家系为材料,在2018,2019年春播和夏播环境下分别进行QTL定位分析。结果表明:玉米穗三叶叶长和叶面积在RIL群体中表现出连续变异,呈正态分布,属于典型的数量性状,性状间呈极显著相关,且广义遗传力分别为88.04%,88.45%,87.86%,85.04%,85.27%和85.73%。2 a共检测到23个QTL,其中控制叶长的QTL 14个,控制叶面积的QTL 9个,分布于玉米的第1,2,4,5,6,8染色体上,单个QTL的表型贡献率为5.84%~17.81%。在春、夏播环境下同时检测到控制叶长的QTL 3个(qFirLL1-2、qFirLL5-1和qSecLL1-2),叶面积QTL 2个(qFirLA2-1和qSecLA2-1),其余位点只能在春播或夏播环境下被单独检测到。在第2染色体(bnlg1316~bnlg1141)和第5染色体(umc1591~umc2298)区间内同时检测到影响穗下叶叶长、穗位叶叶长、穗上叶叶长、穗下叶叶面积、穗位叶叶面积和穗上叶叶面积等6个性状的QTL,贡献率为6.42%~17.81%,为主效QTL位点;这2个标记区间是调控玉米穗三叶叶长和叶面积的重要区段,可能包含调控叶片性状的关键基因。

Leaf length and leaf area are two important agronomic traits,in order to study the genetic mechanism of leaf length and area of three leaves near the ear in maize,a recombinant inbred line(RIL)population(241 lines)derived from Zheng 58 and D863F was used for QTL mapping analysis under spring sowing and summer sowing in 2018 and 2019,respectively.In RILs population,leaf length and area of three leaves near the ear showed continuous variations with a normal distribution and belonged to typical quantitative trait,and significant correlation was found among the traits,the heritability of the six traits was 88.04%,88.45%,87.86%,85.04%,85.27%and 85.73%,respectively.In total,23 QTLs were detected in two years.The number of QTLs for leaf length and leaf area were 14 and 9,respectively.These QTLs with phenotypic variance explained(PVE)ranging from 5.84%to 17.81%were detected on chromosome 1,2,4,5,6 and 8.Among them,only three QTLs(qFirLL1-2,qFirLL5-1 and qSecLL1-2)for leaf length and two QTLs(qFirLA2-1 and qSecLA2-1)for leaf area were identified in both environments(spring and summer sowing),the remaining QTLs can only be detected separately in spring sowing or summer sowing environments.The major QTLs controlling six traits were detected on chromosome 2(bnlg1316-bnlg1141)and 5(umc1591-umc2298),which explained phenotypic variation ranging from 6.42%to 17.81%;These two marker intervals are important for regulating the length and area of three leaves near the ear,and might contain key genes regulating leaf traits.