发掘大豆耐盐基因，对于培育耐盐大豆新种质具有重要意义。申请人项目组前期建立了便捷高效的大豆耐盐性鉴定方法，构建了多个分离群体、收集了多样性丰富的自然群体材料，图位克隆了大豆3号染色体的苗期耐盐重要基因GmSALT3，在野生大豆18号染色体精细定位了耐盐新基因GmSALT18，为耐盐基因的发掘及调控机理研究奠定了基础。但两个基因的遗传关系及其对大豆耐盐性的调控机制尚不清楚。本项目拟图位克隆耐盐新基因GmSALT18，利用遗传转化验证其功能；通过遗传群体及NILs分析明确大豆耐盐基因GmSALT3与GmSALT18的遗传关系；利用转录组测序与生理、生化实验相结合解析两个基因调控大豆耐盐性的分子机制；分析耐盐基因单倍型变异特点及其与大豆耐盐性的关系，开发功能基因分子标记并鉴定其辅助选择效率，为耐盐大豆品种选育提供理论依据。

Soybean, originated in China, is one of the most important crop in China. The evaluation and cloning of salt tolerance genes are important for the utilization of soybean in salinity affected filed in China, therefore increase the planting area and seed yield of soybean. We previously established effective method for evaluation of soybean salt tolerance, created segregating and representative natural populations for gene mapping. Recently, we cloned the soybean salt tolerance gene GmSALT3 through map-based cloning, and fine mapped another tolerance gene on chromosome 18 in wild soybean, which we therefore designated as GmSALT18. However, it remains to be elucidated how these genes work together to conduct salt tolerance of soybean. In this project we propose to isolate GmSALT18 through map-base cloning, analyze the genetic relationship between GmSALT3 and GmSALT18; reveal regulating mechanism of salt tolerance through RNA-Seq, biological and biochemical experiment; analyze the gene haplotypes by systematic comparison of coding and promoter region from representative soybean genetic resources, and determine their relationship with salt tolerance; develop functional molecular markers of the salt tolerance genes and evaluate the selection efficiency in soybean germplasm. We’ll benefit from the better understanding of the biological pathways involved in the regulation of salt tolerance, and the results of this project will provide potential tool for improving salt tolerance in soybean.