ITS2条形码序列对茜草科黎药植物的鉴定

Identification of Li Medicine plants in Rubiaceae using ITS2 barcode sequence

目的利用DNA条形码技术通过ITS2序列对海南茜草科黎药植物进行快速鉴定。方法对样本的核基因ITS2片段进行PCR扩增并双向测序,所得序列经CodonCode Aligner拼接后,利用MEGA5.0软件进行数据分析,并构建聚类树。从ITS2网站上获得ITS2二级结构信息,利用TAXON DNA软件分析序列种内、种间变异并作barcoding gap分析。结果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;各ITS2二级结构种内无明显差异;种间存在明显差异;基于ITS2序列的barcoding gap图显示种内变异和种间变异存在明显的barcoding gap。结论 ITS2序列可以作为DNA条形码对海南茜草科黎药植物进行快速鉴定。

Objective To identify Li Medicine plants in Rubiaceae using DNA barcode technique and ITS sequance. Methods The second internal transcribed spacer （ITS2） of ribosomal DNA was amplified by PCR and sequenced by bidirectional sequencing. Sequence assembly and consensus sequence generation were performed by CodonCode Aligner. The related data analysis was performed using software MEGA 5.0 and the phylogenetic tree was constructed. The ITS2 secondary structure was predicted using ITS2 web server. The distribution of intra- and inter-specific variability was compared using TAXON DNA software and analysed by barcoding gaps. Results In the cluster dendrogram, all species showed monophyletic. There was no obviously distinguished intra-specific difference in ITS2 secondary structure, but there was obviously distinguished inter-specific difference. There are the significant barcoding gap between intra- and inter-specific variations. Conclusion ITS2 sequence could be used as a DNA barcode for the rapid identification of Li Medicine plants in Rubiaceae in Hainan.