基于掖478导入系的玉米叶面积QTL定位

The QTL Mapping for Leaf Area Based on Maize Ye478 Introgression Lines

玉米叶面积与玉米产量密切相关,因而叶面积被当作遗传育种改良的重要目标。本研究利用叶面积具有显著差异的以掖478 (Ye478)为遗传背景的导入系纯合系SL19与Ye478为亲本构建F2作图群体,对3个环境下F2群体单株的穗三叶叶面积进行表型统计分析,利用单标记分析法及IciMapping复合区间作图法对叶面积进行QTL定位。结果显示:2个环境下均于玉米第6染色体umc2068～umc1883区间(3.0 Mb)检测到1个与叶面积相关的QTL,其LOD值分别为4.4和3.0,表型贡献率分别为17.2%和10.9%。该QTL属于主效环境敏感型QTL,且基于表型效应及基因表达水平验证了该QTL真实性。本研究为叶面积的精细定位以及分子标记辅助育种改良玉米叶面积提供重要信息,同时本研究使用的导入系纯合系SL19可直接应用于叶面积遗传改良的实践育种中。

The leaf area is closely related to maize yield, so that leaf area is regarded as an important target for genetic breeding improvement. In this study, the introgression and homozygous lines of SL19 with Ye478 based on the genetic background of Ye478, which had significant differences in leaf areas, were taken as parents to construct F2 mapping population. The phenotypic analysis was performed on the leaf area of trifolium of F2 population in 3 environments. Single marker analysis and IciMapping composite interval mapping were used for QTL mapping of the leaf area. The results showed that 1 QTL related to leaf area was detected to locate at the sixth chromo some umc2068~umc1883 interval(3.0 Mb) of maize in two environments. The LOD values were 4.4 and 3.0, and the phenotypic contribution was 17.2% and 10.9%, respectively. The QTL belonged to the main environmental sensitive QTL, as well as the authenticity of QTL was verified based on phenotypic effect and gene expression level. This study would provide important information for the fine mapping of leaf area and the improvement of maize leaf area by molecular marker assisted breeding. At the same time, the introgression and homozygous line SL19 used in this study could be used directly in the practice breeding of genetic improvement of leaf area.