Analysis of Zingiberaceae in E'mei Area Using ITS2 Sequences / 中国实验方剂学杂志

Objective: To evaluate the use of ITS2 sequences as DNA barcode to identify the Zingiberaceae medicinal plants from E'mei area. Method: The genomic DNAs were extracted from 43 Zingiberaceae medicinal plant samples from Sichuan E'mei area. The ITS2 sequences of these samples were amplified and bidirectionally sequenced by PCR. 40 ITS2 sequences were downloaded from the GenBank,and then the interspecific and intraspecific genetic distances were calculated and analyzed by using MEGA 6.0 to construct Neighbor-joining (NJ) tree; TAXON DNA software was also used to analyze intraspecific and interspecific variations and barcoding gaps. The differences in secondary structure of the ITS2 sequences were predicted and compared. Result: The minimum interspecific distance in Zingiberaceae samples was greater than the maximum intra specific distance,with obvious barcoding gap. The NJ tree showed that the samples were clustered into five different branches,Alpinia,Curcuma,Globba,Hedychium,and Zingiber respectively,and further cluster into sub-branches. Significant differences were also present in the secondary structures of ITS2 between different samples. Conclusion: ITS2 sequences as DNA barcode can be used to conduct accurate and rapid identification of the Zingiberaceae plants and clearly figure out the phylogenetic relationship among them,providing guidance for the study of the distribution of medicinal plants of this genus,as well as theoretical basis for the quality control,medication safety and rational development of Zingiberaceae medicinal plants in E'mei area.

ITS2 sequence analysis and identification of medicinal Artemisia plants / 中国中药杂志

Artemisia hedinii occupies an important position in the Tibetan medicine. Plants in Artemisia vary a lot and are widely distributed in the Qinghai-Tibet Plateau, many plants in Artemisia look similar, making traditional identification methods laborious. In this article, ITS2 sequences were used as DNA barcoding to identify four kinds of confusable Tibetan medicine plants in Artemisia, aiming to establish a rapid and accurate identification methods. Twenty-one samples in Artemisia were collected from the Qinghai-Tibet Plateau, ITS2 sequence PCR amplification and sequencing were conducted after the extraction of DNA. Another 11 sequence downloaded from Genbank were added to the analysis. Genetic distance calculation and analysis, building Neighbor Joining (NJ) phylogenetic tree were conducted by MEGA 6.0, also comparison of secondary structures of ITS2 sequences among samples. A. hedinii, A. annua, A. dubia and A. argyi shared close genetic distance, but the maximum distance between the four species was much greater than the minimum distance within each species, NJ tree showed that the four species went to four separate branches, differences among secondary structures of ITS2 sequences also made it clear to identify these medical plants. It could be an accurate and rapid method for identification and recognition, as well as the evolutionary relationships between the species by using ITS2 sequence as DNA barcode for plants of Tibetan Artemisia. The study provides theoretical basis for quality control, medication safety and rational exploitation.