基于昌7-2导入系发掘干旱胁迫下玉米产量相关QTL位点

以昌7-2为轮回亲本,自交系郑独青为供体亲本,采用回交和定向选择的方法构建高代导入系群体。通过玉米56K芯片对极端株系进行基因分型,以IciMapping逐步回归分析法进行穗重、穗粒重以及百粒重等QTL定位。结果表明,共获得分布于玉米第1、3、5、9、10共5条染色体上的10个QTL位点。其中,与穗重、穗粒重相关的各4个,与百粒重相关的2个。第1、5、10染色体上存在同时控制穗重和穗粒重的相同位点,加性效应均来源于郑独青,贡献率均在22%以上。此外,第10染色体相同位点还同时控制1个微效加性的百粒重QTL。在QTL定位的基础上,获得了多位点聚合的导入系,同时携带第1、5、10染色体上3个QTL位点的导入系,其产量性状表现优于轮回亲本昌7-2。

Identification QTL Loci for Related Yield Traits under Drought Stress Based on Chang7-2 Introgression Lines in Maize

In this study, we developed advanced introgression lines(ILs) using Chang7-2 as the recurrent parent and Zhengduqing as the donor parent, by backcross and directional selection. The 56K maize chip was used to genotype the extreme drought-tolerance lines, and the QTL for drought related traits such as ear weight (EW), seed weight(SW) and hundred grain weight(HGW) were mapped by using software IciMapping with stepwise regression analysis. A total of 10 QTLs were mapped on chr1, 3, 5, 9 and 10, respectively. Among them, 4 QTLs were mapped for EW and SW, 2 QTLs were mapped for HGW, respectively. On Chr1, 5, and 10, there were three same SNP markers controlling EW and SW, and all the additive effects came from Zhengduqing, which could be explained more than 22% of the phenotypic variation. In addition, there also existed one minor effect QTL for HGW with the same SNP markers on chr10. Based on the QTLs mapping results, the ILs with multiple QTLs was obtained. And the ILs carrying three QTLs on chromosomes 1, 5 and 10 have a higher yield than its recurrence parent Chang7-2.