不同水分环境下玉米产量构成因子及籽粒相关性状的QTL分析

干旱胁迫对玉米产量及其相关性状有重要影响。本研究以我国玉米育种骨干亲本齐319和掖478分别和黄早四组配构建的两个F_2:3群体为材料，应用逐步联合分析的QTL定位方法，剖析新疆不同水分环境下(包含水区和旱区)玉米产量构成因子及籽粒相关性状的遗传基础。结果表明，在相同水分处理不同年份间产量构成因子和籽粒相关性状超过70%的QTL可稳定表达，旱区QTL的稳定性明显低于水区，当全部环境联合分析时，各性状QTL稳定性呈现一定程度的降低，但超过60%的QTL仍然稳定表达。两群体中共检测到11个环境钝感的主效QTL(在2个以上环境中检测到，且至少在一个环境下的贡献率大于10%)，分布在bin1.10、2.00、4.09、7.02、9.02、10.04和10.07共7个基因组区段上，除bin10.04外所有环境钝感的主效QTL在全部环境下稳定表达。因此，玉米产量构成因子和籽粒相关性状的QTL在新疆相同水分处理不同年份间，甚至不同水分条件下大部分均可稳定表达，这些主效QTL位点可为抗旱分子育种和进一步精细定位提供参考。

QTL Analysis for Yield Components and Kernel-Related Traits in Maize under Different Water Regimes

Maize yield and yield-related traits are seriously affected by water stress. Therefore, detecting quantitative trait locus (QTL) for yield components and kernel-related traits, analyzing the stability of QTLs and exploiting constitutive QTLs under different water regimes are of great importance in marker-assisted breeding for drought tolerance in maize. In this study two F_2:3 populations derived from Qi319×Huangzaosi (Q/H) and Ye478×Huangzaosi (Y/H) were used to investigate the genetic basis of yield components and kernel-related traits under different water regimes in Xinjiang (including well-water and water-stress environments) by stepwise joint QTL mapping method. The results showed that above 70% of the QTLs for yield components and kernel-related traits expressed stably under the same water regime across the two years. The QTLs detected in water-stress environments were less stable than those in well-water environments across the two years in Xinjiang. The joint analysis combining data of all environments indicated that the stability of the QTLs for all traits decreased, but above 60% of them still expressed stably. A total of 11 constitutive QTLs (with contribution rate more than10% in at least one environment, detected in more than two environments based on single environment analysis) distributed on bin1.10, 2.00, 4.09, 7.02, 9.02, 10.04 and 10.07 were detected in the two populations, and all of them except bin10.04 were stable across all environments. Consequently, most of the QTLs for yield components and kernel-related traits stably expressed under the same water regime across different years, and even under different water regimes in Xinjiang. These constitutive QTLs may provide references for molecular breeding and further basic studies.