玉米耐盐主效QTL位点qFstr1的图位克隆和功能研究

In China, maize is the number one crop in terms of acreage and production due to its versatility. Because of population increase and living standard improvement, more and more corn is needed for our nation. In northeast, northwest and bohai area of our country, there is 1 billion mu saline soil, which has great yield potential of maize. In previous study, a RIL population was constructed using salt-tolerant inbred line F63 and salt-sensitive inbred line F35 as parental lines. A major QTL-qFstr1 was mapped by this population and could explain 58.33% phenotypic variation. Furthermore, the interval of qFstr1 locus was narrowed down to 139 kb using NIL population. By marker assisted selection, this locus was introduced to an elite salt sensitive breeding line and enhanced its salt tolerance ability. In this program, the qFstr1 locus will be cloned by enlarged mapping population and functional studied based on 95% background similarity near isogenic lines. The elite allelic variations of this locus, which will provide genetic resources for maize salt tolerance improvement, will be selected by associate population.

玉米用途极广，已成为我国种植面积最大和总产最高的作物。随着人口增长和生活水平提高，我国对玉米的刚性需求越来越旺盛。我国东北、西北及环渤海地区分布着大约1亿余亩盐碱地，在提高玉米总产方面蕴含着重大的生产潜力。本项目前期利用耐盐亲本F63和盐敏感亲本F35构建RIL群体定位到一个耐盐主效QTL位点qFstr1（可解释表型变异的58.33％），利用NIL群体将该位点的定位区间缩小至139 kb。以耐盐亲本为供体，通过分子标记辅助选择将该位点导入盐敏感骨干育种材料，能够显著提高其耐盐能力，体现了该位点在育种上的重大应用价值。本项目拟通过进一步扩大定位群体，精细定位并最终克隆该主效QTL位点，利用背景相似度达95％的近等基因系研究该位点在玉米盐胁迫下的生理和分子作用机制，并通过关联群体挖掘其优异等位变异，为玉米耐盐育种提供遗传资源。

玉米是我国种植面积最大和总产最高的作物，用途极广。随着人口增长和生活水平提高，我国对玉米的刚性需求越来越旺盛。我国玉米主产区分布着大面积的盐碱地，在提高玉米总产方面蕴含着重大的生产潜力。本项目以前期定位的玉米耐盐主效QTL位点qFstr1（可解释表型变异的58.33％）为基础，图位克隆了候选基因并转基因验证其功能。通过基因表达、亚细胞定位、酵母筛库，并利用背景相似度达95％的近等基因系，研究了该基因/位点在玉米盐胁迫下的生理和分子作用机制。通过自然群体，开发验证功能分子标记，用于玉米骨干亲本的耐盐遗传改良，育成的耐盐改良系在组内广泛用于玉米杂交组合的组配和品种选育。