ITS2序列作为青风藤DNA条形码的研究

Research of ITS2 Sequences as Caulis Sinomenii DNA Barcode

采用DNA试剂盒法提取采自不同地区的青风藤及其类似植物的基因组DNA,设计通用ITS2引物进行PCR扩增和测序,运用生物信息学软件对序列进行分析,从而对青风藤及其类似植物进行分子鉴定。结果表明：产地为陕西、贵州、湖北的青风藤样品序列长度分别为380~437、429~436、434~438 bp,GC含量在54.2%~55.7%,平均GC含量约为55%。青风藤及其类似植物的ITS2序列存在较大差异,且平均K2P遗传距离明显大于青风藤的种内平均K2P遗传距离。这说明内转录间隔区2（ITS2）作为DNA条形码可准确地鉴别青风藤与其他类似植物,为中药材的鉴别提供了新途径。

Using DNA Kit Method to extract genomic DNA from the Caulis Sinomenii and similar plants in different regions, the design of universal ITS2 primers for PCR amplification and sequencing, using bioinformatics software to analyze the sequence, then carried out the molecular identification to Caulis Sinomenii and similar plants. The results showed that the sample sequence length of Caulis Sinomenii in producing area of Shanxi, Guizhou, Hubei respectively were 380~437, 429~436, 434~438 bp and the GC content in 54.2%~55.7%, average GC content was about 55%. There was a big difference between ITS2 sequences of Caulis Sinomenii and similar plants, the average genetic distance of K2 P was significantly greater than the intraspecific average K2 P genetic distance. This illustrated the internal transcribed spacer 2（ITS2） as a DNA barcode can accurately identify Caulis Sinomenii and other similar plants, it provided a new way for the identification of Chinese herbal medicine.