玉米近等基因系群体的构建及其应用

玉米是我国重要的粮食作物,也是研究植物遗传和功能基因组学的理想材料。近等基因系群体是构建分子遗传图谱、QTL定位和分子辅助育种重要的材料。我国广泛栽培的杂交种先玉335和郑单958在植株形态、果穗性状、籽粒含水量和脱水速率等方面存在差异。以郑单958亲本郑58和昌7-2为材料,分别与先玉335的亲本PH6WC和PH4CV进行杂交、回交和多代自交,构建了含有先玉335亲本背景的近等基因系材料的混合群体,利用玉米55K芯片分析了这些材料的基因型和群体结构。对2016年和2017年在廊坊与三亚的2年4点的表型数据进行了性状差异分析及性状间相关性分析,结果表明这些材料在株型、果穗性状、籽粒含水量等方面存在差异。利用该群体,应用全基因组关联分析准确定位到了控制穗轴颜色的基因。未来可利用该群体结合全基因组关联分析,开展株高、穗位、籽粒脱水速率等数量性状的基因定位、分子标记开发和分子辅助育种等工作,提高育种效率。

Construction of Maize Near-Isogenic Lines and Its Application

Maize (Zea mays L.) is an important food crop, and also used as an ideal material for plant genetics and functional genome research. The near-isogenic lines (NILs) are important materials for the construction of molecular genetic maps, quantitative trait locus (QTL) and molecular markers-assisted breeding. Maize hybrids Zhengdan 958 (Zheng 58 × Chang 7-2) and Xianyu 335 (PH6WC × PH4CV) are widely cultivated in China, showing differences in plant architecture, ear traits, grain moisture and dehydration rate, etc. Here, Zheng 58 NILs and Chang 7-2 NILs were conducted by introducing into PH6WC and PH4CV background. These NILs were obtained by consecutively selective backcrossing and selfing, and then genotypes of these NILs were detected using maize 55 K SNP array. These NILs showed different agronomic traits including plant architecture, ear traits, grain water content and dehydration rate. And P1 locus was identified through genome-wide association study (GWAS) analysis of cob glume color on these NILs. In the future, the NILs combined with GWAS could be used to identify genetic factors which determine plant height, ear height, grain filling rate (GFR) and grain dehydration rate (GDR). And SNP molecular markers would be developed for molecular marker-assisted selection breeding to improve breeding efficiency.