大豆促幼苗根系生长关键基因的精细定位与克隆

根系在大豆整个生长发育过程中起着至关重要的作用，定位与克隆大豆促幼苗根系生长的关键基因，对丰富大豆根系分子遗传理论、开展大豆根系分子育种具有重要的理论和应用价值。本研究以前期获得的大豆根系突变体为试验材料，分别构建F2代遗传群体和RIL群体，采用水培法鉴定幼苗根系特征，利用RAD-seq技术筛选与大豆苗期根系生长发育紧密连锁的SNP标记、构建高密度遗传图谱并进行QTL精准定位；综合2个群体遗传图谱的定位结果，筛选稳定、主效QTL。分别以SNP标记和RNA表达谱分析中的显著差异表达基因作探针，对基因组BAC文库进行筛选和鉴定；通过图位克隆和Tail-PCR 两种途径克隆目标QTL。本项目研究的实施，将挖掘和分离大豆苗期促根系生长的重要基因元件，丰富大豆根系生长的分子遗传理论，为利用分子生物学技术调控大豆根系生长发育、提高大豆产量、选育优良新种质提供基因资源和理论依据。

The root plays a vital role in the whole period of growth and development of soybean (Glycine max). The fine mapping and cloning of key genes for promoting soybean root growth at seedling stage is significant for enriching root genetic theory and carrying on root molecular breeding in soybean. In this study, we constructed two populations (F2 generation and RIL population) using a soybean root mutant as test material. The characters of seedling root were investigated with hydroponics. Based on RAD-seq technique, SNP markers tightly linked with soybean seedling root growth and development were screened and high-density genetic maps and QTL precise positioning were made. Associating the two mapping results, stable and main effect QTLs will be selected. The genomic BAC library will be selected and identified using SNP markers and differentially expressed genes as probes. The target QTLs will be respectively cloned by map-based cloning and Tail-PCR. The results of this study will provide gene resources and theoretical basis for regulating soybean root growth and development, increasing soybean yield, and breeding superior new germplasm.