基于掖478导入系的玉米产量性状QTL鉴定

QTL Mapping for Grain Yield Associated Traits Using Ye 478 Introgression Lines in Maize

【目的】鉴定玉米产量相关性状基因位点及包含有利等位基因的导入系,为了解产量性状形成的遗传基础及针对玉米自交系产量性状的分子设计提供参考和依据。【方法】以QB80和Qi319为供体亲本,掖478为轮回亲本,采用回交结合定向选择,分别构建含有61和72个家系的基础导入系群体。通过2年4点田间试验,利用完备复合区间作图进行产量及其相关性状的QTL(quantitative trait locus,QTL)分析。【结果】4个环境下,在QB80为供体的导入系群体中,共检测到9个性状的49个QTL;在Qi319为供体的导入系群体中,检测到9个性状的42个QTL。在2个及以上环境中均检测到的QTL有16个。同一性状在不同环境下所检测的QTL定位在相同的染色体区域,不同性状的QTL也定位在相同或临近的染色体区域,形成多个QTL富集区。2个群体所检测的QTL位点具有较少的一致性,说明2个供体材料中含有不同的有利基因位点。同时,导入片段中含有利基因的导入系,其相关性状明显得以改良,这些导入系可用于QTL聚合以改良掖478的产量相关性状。【结论】QB80较Qi319与掖478间的遗传差异更大,能检测更多的产量性状QTL;2个导入系群体中含有优良等位基因的导入系可用于QTL聚合改良掖478;QTL富集区是为产量性状基因的克隆提供可供参考的重要染色体区域。

[Objective] The purpose of this investigation was to identify QTL （Quantitative Trait Locus） for maize yield related traits and those introgression lines containing favorable alleles. [Method] Two maize inbred lines, QBS0 and Qi319 were used as the donor parents, respectively, and the Ye478 as the recurrent parent, two introgression line populations consisting of 61 and 72 family lines were constructed by backcrossing combined with directional selection, respectively. The two introgression line populations were evaluated across 4 environments in 2 years. The QTLs for yield and related traits were detected by stepwise regression （RSTEP-LRT） using Windows QTL ICI Mapping software. [ Result] A total of 49 QTLs for 9 traits were identified in the population with QB80 as the donor, and 42 QTLs for 9 traits were identified in the population with Qi319 as the donor under four environments. Of which 16 QTLs were detected across not less than two environments. In addition, some QTLs for same trait detected in different environments were located in the same chromosome regions, and those QTLs for diverse traits were also located in the same or adjacent chromosome region, forming several multiple QTL-rich regions. The less consistent QTL was detected in two populations, indicating that the two donors contain different sets of favorable alleles. And the yield associated traits of those lines containing favorable introgression segments or alleles were significantly improved, implicating those lines are available for improving of Ye478 by QTL pyramiding. [ Conclusion ] The genetic difference between QB80 and Ye 478 is more than that of Qi319 and Ye478, therefore, more yield trait QTL can be detected. Those introgression lines containing favorable alleles can be used to improve Ye478 by designed QTL pyramiding. The detected QTL-rich regions have given a subset of important chromosome regions for fine mapping and cloning of genes for yield associated traits.