小麦籽粒钙含量主效QTL QCa.nwafu-1A精细定位与遗传效应解析

缺钙已成为影响人类健康的世界性问题。主食是一种最优安全的钙元素补充途径。小麦是我国主要粮食作物之一，提高其籽粒钙含量对克服缺钙意义重大。目前有关籽粒钙含量QTL精细定位与遗传效应解析鲜有报道。申请人前期利用郑麦7698×周麦19重组自交系和小麦自然群体，通过连锁和关联分析在多环境中鉴定到一个主效QTL QCa.nwafu-1A，定位在1A染色体1.21Mb的物理区间。本研究拟系统评价不同生态条件对籽粒钙含量的影响，筛选高钙含量小麦种质资源；利用已构建好的近等基因系次级F2群体精细定位QCa.nwafu-1A，通过基因序列和表达分析，预测该QTL的候选基因；利用目标QTL靶区间的分子标记鉴定近等基因系BC6F2群体和小麦品种（系）基因型，结合多年多点表型性状数据，解析目标QTL对品质和产量相关性状的遗传效应，明确其在育种上的应用。研究结果将为该QTL的克隆和优异基因资源的开发利用奠定基础。

Calcium deficiency has become a worldwide problem affecting human health. The staple food is an optimal and safe way for calcium nutrient supplementation. Wheat is one of the main food crops in China. Therefore, increasing the calcium content of wheat grain is a great significance in overcoming calcium deficiency. Few studies of fine mapping and genetic effect analysis of QTLs associated with calcium content has been reported yet in wheat grains. In a previous study, we mapped a major QTL QCa.nwafu-1A associated with calcium content to a physical interval of 1.21Mb on chromosome 1A in multiple environments, through linkage and association analyses in the recombinant inbred line (RIL) population of “Zhengmai 7698” × “Zhoumai19” and in a natural population of wheat, respectively. Here, we provide a research proposal of evaluation the effect of various ecological conditions on calcium content in wheat grains and selection the high calcium content wheat germplasm resources. Fine mapping for this QTL using the near isogenic line-derived F2 populations, and predictive the candidate gene(s) by gene sequence and expression analysis. In addition, the QCa.nwafu-1A target interval marker was used to analyze the genotype of the near isogenic line BC6F2 population and the natural population of wheat, combined with multi-year multi-point phenotypic trait data, to analyze QCa.nwafu-1A genetic effects on quality and yield-related traits, and clarify the utilization of the QTL target segment in wheat breeding. This study would provide basis for the map-based cloning of QCa.nwafu-1A, exploitation and utilization of excellent genetic resources for wheat breeding.