基于BSA-Seq技术鉴定大豆耐荫性状相关候选基因

间套种是我国南方大豆种植的重要模式,而高秆作物的遮荫胁迫导致大豆产量和品质难以提升,是制约大豆间套种发挥潜力的限制因素,因此对大豆耐荫性的解析尤为重要。本研究以强耐荫材料矮脚早和极不耐荫材料齐佩华为亲本构建RILs群体,根据耐荫指数表型鉴定RIL群体的耐荫性,从RIL群体中挑选出强耐荫和极不耐荫家系各30个,分别构建成两个极端性状DNA子代混合池,对子代混合池和亲本池分别开展平均60×和30×覆盖深度的全基因组重测序,通过计算两个子代池的SNP-index,比较SNP-index在耐荫池与不耐荫池染色体各区段的差异,定位耐荫性状的关联区域;根据基因注释信息,预测候选基因。结果表明4个样本共得到11 963 077个单核苷酸多态性（SNPs）标记,发现控制耐荫相关性状的基因主要集中在1号染色体51 942~505 708 bp区段、4号染色体50 972 768~51 854 631 bp区段、9号染色体48 778 767 ~50 178 743 bp区段和18号染色体40 858 027~43 909 456 bp区段内,共包含408个基因,通过基因注释和功能分析发现ACC氧化酶5、生长素诱导蛋白5NG4、光敏色素相关丝氨酸/苏氨酸蛋白磷酸酶、转录因子MYBJ6和MYB128等5个基因可能在大豆耐荫过程中起着重要作用,确定为大豆耐荫性的候选基因。本研究结果将为解析大豆耐荫的分子机理奠定重要的基础,同时为大豆耐荫基因的图位克隆奠定坚实的理论基础。

Identification of candidate gene controlling shade-tolerant by BSA-Seq in soybean

Intercropping patterns of soybean is an important model in southern China, the shading stress of high stalk crops is an important factor that affects the yield and quality of intercropped soybean. Therefore, it is particularly important to analyze the shade tolerance of soybean. In this study, a recombinant inbred lines （RILs） established from the shade-tolerant （Aijiaozao） and shade-sensitive （Chippewa）, 30 shade-tolerant and shade-sensitive accessions were selected to construct two DNA hybrid pools, respectively. Progeny hybrid and parent pools were covered for an average depth of 60× and 30×. By calculating the SNP-index of two progeny pools, the differences of SNP-index between shade-tolerant and shade-sensitive chromosomal segments were compared. And the candidate genes of shade tolerance were predicted based on their functional annotations. The results showed that 11 963 077 single nucleotide polymorphisms （SNPs） were obtained from four samples. There were 408 genes were found that they were mainly located on chromosome1 （51 942-505 708 bp）, chr. 4 （50 972 768-51 854 631 bp）, chr. 9 （48 778 767-50 178 743 bp） and chr. 18 （40 858 027-43 909 456 bp）. According to gene annotation and functional analysis, five candidate genes might be related to shade tolerance of soybean, including 1-aminocyclopropane-1-carboxylate oxidase 5-like, auxin-induced protein 5NG4-like, phytochrome-associated serine/threonine protein phosphatase-like, MYBJ6 and MYB128 were identified. They might play an important role in the process of soybean shade tolerance. The results will lay an important foundation for the molecular mechanism of soybean shade tolerance, and laid solid theoretical foundation for map-based cloning of shade-tolerant genes in soybean.