玉米磷信号途径调控基因序列变异及其与耐低磷性状的关联分析

Phosphorus is an essential element for plant growth and development. In southwest China, most soil is deficient for available phosphorus and application of phosphorus fertilizer for crops is a necessary measure to ensure harvesting normal grain product. However, the utilization of phosphorus for crops is very low, which leads to environment pollution and resource depletion of phosphate rock. Development of variety with high utilization efficiency of phosphorus is the fundamental approach to solve this problem. In this proposal, on the basis of germplasm screening, genetic and molecular mechanism for low phosphorus stress in maize, key regulatory genes in Pi-signaling pathway such as ZmPHR and ZmPHO will be assayed for DNA sequence diversity and favorable allele mining of phosphorus utilization using association analysis and molecular technology. We expect this study will supply not only technological tools for molecular breeding of improving Pi utilization but also relevant theory for understanding molecular responsive mechanism of low phosphorus stress in maize.

磷是植物生长发育必需的大量元素。我国西南地区多数土壤有效磷严重不足，且磷肥的当季利用率很低，导致水土污染及对磷矿资源的不可再生消耗。解决此问题最有效的途径就是培育并推广耐低磷新品种，提高作物磷利用效率。本项目将在对玉米磷利用性状的资源、遗传和分子机理研究基础之上，以磷信号通路中ZmPHR和ZmPHO等关键调控因子为候选基因，通过关联分析及其他分子生物学方法，分析目标基因在遗传多样性玉米种质中的序列变异，挖掘耐低磷性状的优良单体型并开发功能分子标记，为开展玉米磷高效分子育种提供技术和理论参考。

本项目利用300余份关联群体的56K SNP芯片数据，结合低磷处理和对照条件下玉米苗期相关表型的数据进行全基因组关联分析，共找到212个显著关联位点和187个相关候选基因，其中与根系干重系数关联的涉及20个候选基因，从中筛选出磷高效利用相关的关键候选基因（ZmPHO1，ZmPHR1和ZmPAT1等）。通过重测序的方法在关联群体中获取这些进基因的全长，解析目标基因在遗传多样性玉米种质中的序列变异，挖掘耐低磷性状的优良单体型并开发功能分子标记，同时利用分子生物学方法进一步对其功能进行研究，为开展玉米磷高效分子育种提供技术和理论参考。通过本项目的资助，发表了SCI收录论文6篇；培养了研究生5名；申报了国家发明专利5项，其中2项已授权。