棉花窄卷苞叶基因fg的精细定位

Fine mapping of the frego bract gene fg in cotton

【目的】窄卷苞叶可以减少棉花苞叶碎屑的附着,有助于降低机采棉含杂率。对棉花窄卷苞叶基因fg进行精细定位,为该基因的图位克隆和育种利用提供参考。【方法】以陆地棉T582为母本,分别与父本陆地棉TM-1、海岛棉3-79杂交构建2个F2分离群体;其中群体1(T582×TM-1)包含370个单株,群体2(T582×3-79)包含2667个单株。根据TM-1和3-79参考基因组数据,利用开发的插入缺失(insertion-deletion,Indel)标记对fg进行精细定位。利用棉花功能基因组学和多组学数据,对定位区间内的基因进行功能注释及表达模式分析。【结果】遗传分析结果表明,棉花窄卷苞叶由隐性单基因控制。在前人对fg基因初定位的基础上,进一步将窄卷苞叶基因fg定位在A03染色体分子标记M3与M4之间,区间大小为188 kb。预测定位区间内有14个注释的功能基因。其中,Gh_A03G021700、Gh_A03G021900、Gh_A03G022600和Gh_A03G022700基因在花萼、副萼中的表达量较高。【结论】棉花窄卷苞叶fg基因被精细定位在A03染色体188 kb区间内,并初步分析了定位区间内的14个候选基因,为该基因的图位克隆奠定了基础。

[Objective]Frego bract can greatly reduce the attachment of bract to boll and help to reduce the percentage of trash of machine-harvested cotton.In this study,we aimed to fine mapping the frego bract fg gene in cotton,so as to provide reference for its cloning and breeding utilization.[Method]Two F2 segregating populations were constructed by crossing Gossypium hirsutum T582(as the female parent)with G.hirsutum TM-1 and G.barbadense 3-79,respectively.Population 1(T582×TM-1)included 370 individual plants,and population 2(T582×3-79)contained 2667 individual plants.The developed Indel(insertion-deletion)markers based on the reference genomic data of TM-1 and 3-79 were used to fine mapping fg.Functional annotation and expression pattern analysis of genes within the mapped sequence were performed using cotton functional genomics and multi-omics data.[Result]Genetic analysis showed that frego bract is controlled by a single recessive gene.Based on the previous mapping result of fg gene,cotton fg gene was further mapped between molecular markers M3 and M4 on chromosome A03,with an interval size of 188 kb in this study.A total of fourteen annotated functional genes were predicted in the mapping region.Among them,Gh_A03G021700,Gh_A03G021900,Gh_A03G022600 and Gh_A03G022700 were highly expressed in sepal and epicalyx.[Conclusion]Frego bract fg gene was finely mapped on chromosome A03,with an interval size of 188 kb,and 14 candidate genes in the mapping interval were preliminarily analyzed,which lays the foundation for map-based cloning of this gene.