茄子果色上位基因的精细定位

The Peel color of eggplant is an important appearance quality, and also one of the first important breeding objects for breeders. The peel color of eggplant is a complex trait controlled by multiple genes, and its heredity is relatively complicated. During our breeding practice, it was found in some combinations, when two inbreeds with white peel color were crossed, the peel color of their F1 hybrids was red purple, and it was concluded the inheritance of peel color in this case was controlled by 2 epistatic gene loci. On the basis of previous results, parents both with white peel color and their F2 segregating populations will be used to map the epistatic genes controlled peel color by methods of combination of SLAF-seq and BSA. Firstly, the target genes will be preliminarily mapped to the hot region of the genome, where the distribution of SNP and InDel markers linked with peel color are focused. Secondly, more than 1500 of F2 individuals will be screened for the recombinant plants, meanwhile, higher density SNP and SSR markers will be further developed and be used to fine map epistatic genes controlling eggplant peel color. Finally, gene annotation will be done in fine mapping regions to screen candidate genes for 2 epistatic gene loci. The study not only could obtain molecular markers closely linked to epistatic genes, providing reliable markers for eggplant peel color selection, but also could screen the candidate genes in the closely hot regions by bioinformatics, laying the foundation for eventually clone of the epistatic genes.

茄子果色是重要的商品外观品质，是首要的育种目标之一。茄子果色是多基因决定的复杂性状，遗传相对复杂。项目组育种中发现有些组合2个白果色的亲本杂交后F1代果色为紫红色，遗传规律分析表明其果色遗传受2对上位性基因控制。本项目在前期研究基础上，以白果色父、母本及其F2分离群体为材料，首先利用SLAF-seq技术并结合BSA法找到与茄子果色性状连锁的SNP和InDel标记集中分布的基因组区域，即关联区域，初步定位上位基因；然后以1500株以上F2群体为材料，进行重组株筛选，并在关联区域内加密SSR和SNP分子标记，得到与果色连锁更精密的标记，精细定位上位基因；最后在精细定位区间进行基因注释，从中筛选候选基因。本研究结果可以获得与茄子果色上位基因紧密连锁的分子标记，为茄子果色分子标记辅助选择育种提供可靠标记；同时也可以通过紧密关联区域内的生物信息学分析筛选候选基因，为上位基因的最终克隆奠定基础。

茄子果色是重要的商品外观品质，是首要的育种目标之一。茄子果色是多基因决定的复杂性状，遗传相对复杂。项目组育种中发现有些组合2个白果色的亲本杂交后F1代果色为紫红色，遗传规律分析表明其果色遗传受2对上位性基因控制。在次基础上，本项目以白果色父、母本及其F2分离群体为材料，开展以下研究内容：首先利用SLAF-seq技术并结合BSA法找到与茄子果色性状连锁的SNP和InDel标记集中分布的基因组区域，即关联区域，初步定位上位基因；然后加大F2群体，进行重组株筛选，并在关联区域内加密分子标记，得到与果色连锁更精密的标记，精细定位上位基因；最后在精细定位区间进行基因注释，从中筛选候选基因。本项目研究结果如下：（1）将控制茄子果色的上位基因D定位在10号染色体，P基因定位在8号染色体;（2）开发了与茄子果色上位基因D紧密连锁的InDel 22522标记，与上位基因P紧密连锁的InDel 5513标记；（3）初步确定10号染色上的控制茄子果色上位D基因为SmMYB1基因，8号染色上的控制茄子果色上位P基因为SmANS基因；（4）通过VIGS体系证明了SmMYB1和SmANS基因在茄子果皮花青素合成中发挥作用。本项目获得的与茄子果色上位基因紧密连锁的分子标记能够加速育种进程；茄子果色上位性基因的精细定位及候选基因分析，为揭示茄子果色上位性遗传分子机制奠定了基础。