基于BSA-Seq技术挖掘大豆中黄622的多小叶基因

Mapping of an incomplete dominant gene controlling multifoliolate leaf by BSA-Seq in soybean(Glycine max L.)

栽培大豆(Glycine max)叶片一般为三出复叶,也有个别品种或植株突变体产生4~7个小叶,为多小叶。复叶的形成使植物对外界环境的适应能力增强,对大豆多小叶相关基因的挖掘和研究有助于改善大豆农艺性状和产量表现。本研究从大豆栽培品种中品661的突变体库中鉴定出一个多小叶突变体——中黄622,每个复叶有4~9个小叶。利用该突变体与中品661配制组合,分别于北京和海南调查F_2和F_(2:3)植株叶片表型,结果表明,多小叶性状受1对不完全显性基因控制。采用BSA-seq方法进行定位,利用F2正常三出复叶和多小叶个体分别构建混池,测序结果与参考基因组平均比对效率为98.83%,平均覆盖深度为32.75×,基因组覆盖度为99.22%。ED方法关联分析发现,在11号染色体定位到2个区域,总长度为5.29 Mb,共包含1103个基因。根据SNP-index方法关联分析,当置信度为0.99时,在11号染色体鉴定出3个区域,总长度为3.42 Mb,共包含701个基因。2种关联分析方法同时定位的基因有690个,亲本之间存在SNP的基因有6个。本研究结果为大豆多小叶基因图位克隆奠定了基础。

The leaves of cultivated soybean(Glycine max L.) are comprising of three leaflets in general,but there are also individual varieties or mutants which have a high frequency of compound leaves with 4-7 leaflets,named multifoliolate leaves.Compound leaf formation enhances the plant’s ability to adapt to the external environment.Study of related genes to multifoliolate leaves might contribute to the improvement yield level of and soybean agronomic traits.In this study,a multifoliolate leaf mutant Zhonghuang 622 was identified from the mutant library of soybean cultivar Zhongpin 661,which had 4-9 leaflets in each compound leaf.The compound leaf phenotypes of F2 and F2:3 population from a cross between Zhongpin 661 and Zhonghuang 622 were investigated in Beijing and Hainan,respectively.Analysis of phenotypic data from F2 and F2:3 population revealed that the multifoliolate leaf trait was controlled by an incomplete dominant gene.BSA-Seq method was used for gene mapping.The two bulks of normal trifoliate and multifoliolate individuals in F2 population were constructed and sequenced for an average depth of 32.75 x,which covered 99.22% genome compared to the reference genome.Through correlation analysis of mixed pool sequencing results by ED method,two regions were located on chromosome 11,with a total length of 5.29 Mb and a total length of 1103 genes.Three regions were identified on chromosome 11 at confidence of 0.99,with a total length of 3.42 Mb and a total of 701 genes by the association analysis of SNP-index method.There were 690 genes located simultaneously and six SNP genes between parents by the two association analysis methods.These results lay the foundation for map-based cloning of the genes related to compound leaf development.