贵阳花溪古茶树遗传进化的SNP分析

试验采用SNP(单核苷酸多态性)技术对贵阳花溪古茶树资源的遗传多样性、群体结构和遗传进化进行了分析.结果表明,利用生物信息学分析古茶树样品的重测序数据,获得了1 656 258个SLAF标签,古茶树样品平均测序深度为24.21x,其中多态性的SLAF标签有462 897个,共得到283 376个高一致性的群体SNP标记.从基于SNP标记获得的进化树可以看出,来自相近地方的古茶树在进化树上基本上处于相近位置,但是花溪古茶树存在着广泛的遗传变异,主成分分析(PCA)获得了与进化树一致的结果.群体结构分析可清晰地把古茶树资源分为乔木型和灌木型2个类群.乔木型古茶树位于进化树下部,而灌木型古茶树处于进化树上部,表明茶树是由乔木型向灌木型进化的.

SNP Analysis of the Genetic Evolution of Ancient Camellia sinensis Trees from Huaxi, Guiyang

In the present study, the SNP (single nucleotide polymorphism) technique was used to analyze the genetic diversity, population structure and genetic evolution of ancient Camellia sinensis trees from Huaxi, Guiyang. In bioinformatics analysis of the resequencing data, with an average sequencing depth of 24.21x, a total of 1, 656, 258 SLAF tags were obtained, of which 462, 897 were polymorphic SLAF tags and 283, 376 were highly consistent population SNP markers. The phylogenetic tree analysis based on these SNP markers indicated that there existed abundant genetic variation among Huaxi tea accessions, and the accessions from the same place were generally clustered together, which was further verified by principal component analysis (PCA). Population structure analysis divided these resources into two distinct groups:an arbor-type group and a shrub-type group. The arbor group and the shrub group were located at the bottom and the top of the phylogenetic tree, respectively, indicating that the teas evolved from the arbor type to the shrub type.