[ Objective] The aim of this paper was to investigate the genetic diversity of mitochondrial DNA D-loop sequences of Cheilinus undulatus populations. [Method] Twenty-five individuals of C. undu/atus were collected from the offshore area of Hainan Province. PCR and cloning techniques were used to clone and purify the mtDNA D-loop sequences of C. undu/atus populations （n =25）, about 1 400 bp long PCR product was obtained. ClustalX software was adopted for sequence alignment, and results were imported into MEGAS. 0. [ Result] According to experimental results, 66 mutation sites were detected from 25 individuals, including 0 deletion, 4 inserts, 59 transition sites, 2 transversion sites and 1 transition-transversion site. Pairwise genetic distances of these 25 individuals were calcu- lated by using MEGA5.0 software. Based on that, NJ phylogenetic tree of these 25 individuals was constructed. Analysis of C. undulatus populations using DNASP software showed that the polymorphic site number （S） was 62, nucleotide diversity （Pi） was 0.006 06, and average number of nucleotide differences （K） was 6. 907. [ Conclusion] Overall, there was no significant variation among mtDNA D-loops of C. undulatus populations. Key words
研究以海南陵水、马来西亚、西沙、南沙4个海域共101尾波纹唇鱼作为研究对象,通过线粒体DNA的COⅠ和Cytb基因序列分析方法对波纹唇鱼进行了遗传多样性研究。经PCR扩增、克隆与序列测定,分别获得1560 bp COⅠ基因和1141 bp Cytb基因序列。两者多态性遗传参数统计显示,101尾个体分别存在23(COⅠ)和30(Cytb)个变异位点,分别检测出20(COⅠ)和27(Cytb)个单倍型,总群体单倍型多样性(Hd)分别为0.629(COⅠ)和0.755(Cytb),平均核苷酸差异数(K)分别为1.195(COⅠ)和1.424(Cytb),核苷酸多样性指数(Pi)分别为0.00077(COⅠ)和0.00126(Cytb)。分子方差分析(AMOVA)结果分别为26.26%(COⅠ)和4.22%(Cytb)的变异来自群体间,73.74%(COⅠ)和95.78%(Cytb)的变异来自群体内。同时,两个基因的单倍型网络图呈星状放射结构,不同地理来源的单倍型无明显分支,呈交错分布,没有体现地理差异性。研究初步认为,波纹唇鱼的遗传多样性处于较低水平,遗传分化存在但不显著,该结果可为今后波纹唇鱼的种质资源保护工作提供必要的科学依据。
