山药原植物薯蓣及其近缘种的分子鉴别和亲缘关系研究

采用CTAB法提取总DNA,应用PCR产物直接测序法,测定了山药原植物薯蓣及其近缘种共10个种和1个变种的trnL-F和rbcL序列.序列分析结果表明:薯蓣及其近缘种trnL-F序列长689～834 bp,当空位始终作缺失处理时,有变异位点67个,其中信息位点11个,占序列总长度的1.43%;种间碱基差异百分率为1.6%,其中转换率为0.6%,颠换率为1.0%;序列的G C含量为32.5%.薯蓣及其近缘种rbcL序列长1 096～1 160 bp,存在变异位点42个,其中信息位点10个,占序列总长度的0.93%;种间碱基差异百分率为0.6%,其中转换率为0.3%,颠换率为0.3%;序列G C含量为44.1%.基于2个序列分别重建了薯蓣及其近缘种的系统发育树.结果表明2个系统树的结构基本一致,均支持经典分类方法对薯蓣及其近缘种的亲缘关系的划分.同时,本研究也证实叶绿体基因组序列测定是鉴定山药原植物薯蓣及其近缘种的快速、可靠、有效的方法.

Molecular authentication and relationships of Dioscorea olystachya Turcz.and its related species

The total DNA was isolated by CTAB and the PCR products were applied to sequence directly.cpDNA trnL-F and rbcL of Dioscorea polystachya Turcz.and its related species were analysed.The results showed that the length of trnL-F was 689-834 bp.When the gaps were always treated as missing,there were 67 variable sites,of which 11 were porsim-info ones,and account for 1.43% of the total length.The percentage of(G+C)content was 32.5%.The pairwise distance between species was 1.6%,of which 0.6% was transistions and 1.0% was the transversions.For rbcL,the total length was 1 096-1 160 bp.When the gaps were always treated as missing,there were 42 variable sites,of which 10 were parsim-info ones,and account for 0.93% of the total length.The pairwise distance between species was 0.6%,of which the transistions and the transversions were both 0.3%.The percentage of(G+C)content was 44.1%.Based on the two sequences,the phylogeny trees were constructed by bootstrap test.The trees held the same point with the classification according to the morphology and anatomy.Besides,this research also proved that the cpDNA sequecing was rapid,efficienly,credible way to distinguish D.polystachya Turcz.and its related species.