基于ITS2序列的5种鬼臼类中药材DNA条形码鉴定研究

目的通过分析5种鬼臼类中药材八角莲、南方山荷叶、桃儿七、小八角莲和六角莲的ITS2(internal transcribed spacer2)条形码序列,探讨鬼臼类药材鉴定新方法。方法共收集26份样品,以ITS2作为条形码序列,对各鬼臼类中药材提取基因组DNA,PCR扩增ITS2序列并进行双向测序。所得序列经Codon Code Aligner拼接并剪切后,采用MEGA5.1软件进行序列对比分析,计算遗传距离,分析比较种内、种间序列差异,并构建系统邻接树。结果 5种药材种间存在明显差异,各个种的种内最大遗传距离均小于种间最小遗传距离;构建的系统树各个种不同样本均分别聚在一起,表现出单系性。结论ITS2序列作为DNA条形码可较好地用于鬼臼类中药材DNA条形码的鉴定研究。

DNA molecular identification of Chinese herbal materials of Dysosma by ITS2 barcode sequence

Objective To explore a new identification method for medicinal materials of Dysosma, and analyze the second internal transcribed spacer (ITS2) barcode sequences of Diphylleia sinensis and Dysosma versipellis, Sinopodophyllum hexandrum, Dysosma difformis and Dysosma pleiantha in five kinds of podophyllum. Methods The ITS2 of ribosomal DNA of medicinal materials of podophyllum was amplified and sequenced by bi-directional sequencing of PCR products. Sequence assembly and consensus sequence generation were performed by using CodonCode Aligner. Phylogenetic study was performed using software MEGA 5.1 in accordance with Kimura-2-parameter (K2P) model. Genetic distances were calculated and analyzed and the phylogenetic tree was constructed by using the neighbor-joining (NJ) method. Results There were significant differences among five kinds of Dysosma. Their maximum intraspecific genetic distance (K2P distance) was far lower than their minimum interspecific genetic distance with the other species. In the cluster dendrogram, all species showed monophyletic. Conclusion ITS2 sequence as DNA barcoding technique can be used to identify Chinese herbal materials of Dysosma.