为验证DNA 条形码序列在物种鉴定方面及物种的系统发育方面的广适性，本研究以黎药植物木麻黄为研究对象，收集木麻黄及其近缘种和混伪品22 份样本，采用4 对引物（ITS，ITS2，trnH-psbA ，rbcL）分别进行PCR 扩增，产物进行双向测序。利用CodonCode Aligner 软件进行序列的拼接，采用MEGA5.1 进行数据的处理。结果表明，利用ITS/ITS2 可以区分木麻黄与其近缘种以及混伪品，样品的psbA -trnH，rbcL 和ITS/ITS2 4 个序列中，ITS/ITS2 序列具有明显的DNA gap。基于ITS/ITS2 序列构建的NJ 树结果表明，木麻黄属所有样品聚为一类，呈现明显的单系性，与其亲缘关系较近的是藤黄科。因此，ITS/ITS2 序列可以准确鉴定黎药的基原植物。并能从分子水平揭示木麻黄的系统演化规律。

In this research, Casuarina eguisetifolia Linn was used to verify the broadly suitability of DNA barcodes in identification of Li-medicine plants and systematic development of species. The genomic DNA of 22 samples collected C. eguisetifolia and its adulterants were amplified by 4 pairs of primers respectively (ITS (internal transcribed spacer), ITS2 (internal transcribed spacer 2), trnH -psbA , rbcL) and sequenced bi-directionally. Obtained sequences were assembled using CodonCode Aligner. The dates were analysised using MEGA5.1 in accordance with the kimura 2-parameter (K2P) model. The neighbor-joining (NJ) phylogenetic trees were constructed. Our study demonstrated the efficacy of ITS/ITS2 to distinguish between C. eguisetifolia and other adulterants species at the molecular level. Comparative to the primer of trnH -psbA and rbcL, there was a obviously DNA gap. The NJ trees showed that the several species of Casuarina can be classified to same types to show a obviously monophyly, which the nearest family was Guttiferae. Therefore, ITS/ITS2 regions can accurately distinguish the original plant of Li-medicine. The systematic evolution of Casuarina can be verified in the molecular level.

海口市科技工业信息局重点科技项目（2011—0036）：黎药的DNA 条形码研究，负责人：唐历波。