苞叶姜的nrDNA ITS2和cpDNA psbB-H序列 分子进化特点的分析

采用改良的CTAB法从硅胶干燥的苞叶姜(Pyrgophyllum yunnanense)叶片中提取总DNA,对nr DNA ITS2和cp DNA psb B-H区域进行PCR扩增、测序和序列分析,初步研究2套植物基因组的变异速率。nr DNA ITS2序列长224 bp,有变异位点3处,变异位点百分率为1.339%,(G+C)含量为60.7%。cp DNA psb B-H序列长623~625 bp,有2个碱基插入缺失,变异位点8处,变异位点百分率1.284%,(G+C)含量为33.9%,cp DNA核苷酸多态性(0.00551)比nr DNA(0.00295)高。苞叶姜的这2个片段,变异速率相近,遗传分化指数相同(Fst=1.000),居群间高度分化。ITS2序列和psb B-H序列单倍型中性检验结果一致,表明苞叶姜居群处于长期稳定状态。psb B-H错配分布(Mismatch-distribution)分析,表示苞叶姜的现有分布范围近期可能经历了居群扩张。因此,苞叶姜的谱系地理学研究可结合nr DNA ITS2序列和cp DNA psb B-H序列来分析。

Characterizing molecular evolution of Pyrgophyllum yunnanense (Zingiberaceae ) based on nrDNA ITS2 and cpDNA psbB-H sequence analysis

Using total DNA extracted from silica-dried leaves of Pyrgophyllum yunnanense using modified CTAB method,the nrDNA ITS2 and cpDNA psbB-H regions were amplified and sequenced.Differences between the nrDNA ITS2 and cpDNA psbB-H sequences in Pyrgophyllum yunnanense were analyzed.The length of ITS2 sequence of Pyrgophyllum yunnanense was 224 bp,of which three variable sites with a 1.339％ rate were observed.The (G+C) content was 60.7％.The length of psbB-H sequence of Pyrgophyllum yunnanense was 623-625 bp,of which eight variable sites with a 1.284％ rate were observed.The (G+C) content was 33.9％.The evolutionary rate of the ITS2 and psbB-H regions in Pyrgophyllum yunnanense was similar.The fixation index (Fst=1.000) indicated high population genetic differentiation.The neutrality test values showed the populations of Pyrgophyllum yunnanense had been stable for a long time.The test of mismatch distribution using cpDNA genome showed that the populations in the entire geographical region had undergone recent range expansion.We suggested using nrDNA ITS2 and psbB-H sequences of Pyrgophyllum yunnanense to investigate the phylogeographic study of this specie.