[ITS2 sequence analysis and identification of medicinal Artemisia plants]

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.