野生大豆抗虫位点的遗传解析及相关基因的功能鉴定

The damage to plant caused by herbivorous insects reduces the yield and quality of soybean seed. Insect can reduce yields by as much as 100 % if it is not controlled. Wild soybeans (Glycine soja) have a broad pool of potentially useful genetic resources. Only half of the resistance alleles in wild soybean are maintained in cultivated soybean after domestication combined with both artificial and natural selection in addition to sampling fluctuation. In our preliminary experiment, more than 47% lines showed resistance to CCW and four traits related to soybean resistance to insect had a large variation in this wild soybean population. In this project, we will identify the QTLs and genes related to insect resistant in wild soybean using association analysis and linkage analysis. The function of candidate gene will be expound by molecular biology methods, such as expression analysis, resequencing, and targeted genome editing technology. The results of this project would be elucidate the genetic basis of soybean resistance to insect and the regulation mechanism and the molecular evolution of candidate gene. The results would also provide theoretical guidance and genetic resources for the utilization of wild soybean in soybean insect resistance and broadening the genetic basis of cultivated soybean.

虫害是影响大豆产量和品质的一个重要因素，如不加以控制，对大豆产量造成的损失高达100%。研究表明，野生大豆资源中蕴含丰富的抗性基因，驯化和选择使现代栽培大豆丧失了野生大豆中一半的抗性基因。项目组前期研究发现野生大豆中47%的材料表现为抗虫，4个抗虫相关指标在自然群体内都表现出较大的遗传变异。本项目将利用关联分析和连锁分析发掘野生大豆中抗虫等位基因，并通过差异表达、重测序和定向基因组编辑技术等分子生物学手段研究候选基因的功能及作用机制。研究结果可望阐明大豆抗虫性的遗传基础，候选抗虫相关基因的转录调控机制及其分子进化，为利用野生大豆的基因提高栽培大豆的抗虫性、拓宽栽培大豆的遗传基础提供理论和新的基因资源。

野生大豆[Glycine soja Sieb. & Zucc.]是栽培大豆的近缘种，与栽培大豆相比，具有更多的抗逆基因和遗传多样性，是挖掘抗性基因、拓宽栽培大豆遗传基础的理想资源，但在大豆抗虫方面相关研究较少。在此背景下，本项目开展了野生大豆抗虫性评价、野生大豆抗虫资源挖掘、抗虫性位点定位、抗虫候选基因挖掘、功能鉴定及其抗虫性机理探索等方面的研究。通过项目实施，从野生大豆自然群体中筛选出5份高抗和8份高感材料；检测到2、9、34个SNP分别与幼虫重、虫害指数、抗性等级显著相关；利用RNA-Seq分析，发现斜纹夜蛾诱导后野生大豆的转录组发生重塑，抗、感性材料对斜纹夜蛾诱导后的响应不同；对两个抗虫性相关的大豆基因GmPT1和GmVQ58进行功能研究，初步明确这两个基因负调控大豆对斜纹夜蛾的抗性，两个基因都具有较好的育种应用潜力；GmVQ58可能通过与GmWRKY32的互作调控大豆抗虫性。该项目所得结果为大豆抗虫育种提供了可利用的抗虫资源、具有育种利用价值的候选基因和抗虫理论基础。