基于BSA分析定位控制西藏大麦侧小穗发育的基因

Mapping loci that control lateral spike development in Tibetan barley by bulked segregant analysis(BSA)

大麦侧小穗结实与否导致了二棱/六棱性状的分化,从而显著影响其籽粒产量,因此大麦二棱到六棱的变化具有显著驯化特征.青藏高原野生和栽培大麦资源丰富,被认为是栽培大麦的驯化和遗传多样性中心之一.为进一步了解大麦棱数调控的遗传基础以及西藏栽培大麦驯化的过程,以西藏野生二棱大麦和六棱大麦地方品种为亲本构建遗传分离群体,遗传分析发现二棱性状受单个显性基因位点控制.通过集群分离法(Bulked segregant analysis,BSA)分别建立含有22个F2单株的二棱混池和六棱混池,基于SLAF-seq(Specific-locus amplified fragment sequencing)技术共获得456 691个SLAF标签,通过SNP-index和ED两种关联算法交集得到3个与棱数性状相关的侯选区域,总长度为53.84M b,包含536个基因,其中能分别被3个数据库GO、K EGG和COG注释的基因有413、189和160个基因.上述研究实现了对控制西藏大麦侧小穗发育性状相关基因的初步定位,结果可为后续目标基因的精细定位和克隆提供理论参考.

Fertility of lateral spikelets determines the two-rowed or six-rowed spikes of barley (Hordeum vulgare L.), which results in significantly different grain yields. The change in row type from two-rowed to six-rowed shows remarkable domestication characteristics. The Qinghai-Tibet plateau has abundant resources of wild and cultivated barley, and is considered one of the centers of domestication and genetic diversity of cultivated barley. In order to obtain a primary understanding of the genetic basis of lateral spike development regulation and the domestication process in cultivated Tibetan barley, an F2 segregation population was constructed by crossing the two-rowed wild barley accession ZYM0083 with the six-rowed landraces Linzhiheiliuleng. Genetic analysis showed that the row type was controlled by a single gene. Using the specific-locus amplified fragment sequencing (SLAF-seq) technology and bulked segregant analysis (BSA), two DNA pools from 22 two-rowed spike individuals and 22 six-rowed spike individuals of the F2 population were constructed and sequenced. A total of 456 691 SLAF tags were obtained. By adopting the ED and SNP index for association analysis, three candidate regions with a 53.84-Mb interval and containing 536 genes were obtained. Four-hundred thirteen, 189, and 160 annotated genes were acquired by GO, KEGG, and COG libraries, respectively. Loci that control lateral spike development in Tibetan barley were primarily mapped by SLAF-seq, and the results presented in this study will facilitate the fine mapping and cloning of target genes.