应用ITS2条形码鉴定中药材合欢皮、合欢花及其混伪品

Identification of Albiziae Cortex,Albiziae Flos and their adulterants using ITS2 barcoding

为准确鉴别中药材合欢皮、合欢花及其混伪品,该研究应用ITS2条形码对46份药材及其混伪品进行鉴定研究。通过对样本进行基因组DNA提取,PCR扩增和双向测序获得ITS2序列。所得序列经CodonCode Aligner拼接后,基于隐马尔可夫模型的HMMer注释方法去除两端5.8S和28S区段,用软件MEGA5.0对序列进行分析比对,并基于K2P模型进行遗传距离分析。采用相似性搜索法、最近距离法、构建NJ树对序列鉴定能力进行评估。结果表明,药材基原物种合欢的ITS2序列种内最大K2P遗传距离均远小于其与混伪品的种间最小K2P遗传距离;应用相似性搜索法分析结果表明ITS2序列可准确鉴定合欢药材及其混伪品;NJ树显示合欢药材与其混伪品可明显区分开,表现出良好的单系性。因此,应用ITS2条形码可稳定、准确地鉴别合欢药材及其混伪品。

The ITS2 barcode was used to accurately identify Albiziae Cortex, Albiziae Flos and their adulterants in this study. A total of 46 samples from Albiziae Cortex, Albiziae Flos and their adulterants were collected. The ITS2 regions were amplified and sequenced. Sequences were assembled using the CodonCode Aligner. The genetic distances of ITS2 region were calculated using MEGA 5.0. BLAST1, nearest distance and phylogenetic tree （NJ-tree） methods were used to assess the identification efficiency of the ITS2 barcode. The results revealed that the intraspecific genetic distances of Albizia julibrissin were lower than the interspecific genetic distances between A. julibrissin and its adulterants. The identification efficiency of ITS2 barcode using BLAST1 was 100%. The NJ-tree showed that A. julibrissin and their adulterants can be easily differentiated according to their monophyly. The ITS2 barcode is suitable to be as a barcode to identify Albiziae Cortex, Albiziae Flos and their adulterants.