Identification and analysis on medicinal plants of Labiatae from Emei Mountain Area Using ITS2 and matK sequences / 中草药

ABSTRACT

Objective: To evaluate the efficiency of ITS2 and matK DNA barcode for the identification the Labiatae medicinal plants in Emei Mountain. Methods: A total of 23 samples of Labiatae medicinal plants were harvested in Emei Mountain. The DNA was extracted and used for PCR to obtain the ITS2 sequences. Meanwhile, 54 ITS2 and 51 matK sequences of the medicinal plants in Labiatae were downloaded from Genbank. The interspecies and intraspecific genetic distance and sequence variation sites of all sequences were determined by MEGA 5.0 software. The Neighbor Joining (NJ) phylogenetic tree was constructed, and barcoding gap analysis was then performed. Results: The length of various ITS2 sequence was distributed from 190 to 237 bp, with GC content of 53%-73%. Moreover, significant barcoding gap was observed when comparing the distances, the recognition rate for plants of the Labiatae family was 94%.The barcoding gap of the matK sequence was not significant, there was obvious overlap, and the recognition rate for the Labiatae family was 96%. Conclusion: ITS2 has a better ability to identify Lamiaceae plants at the species level, but the matK sequence has a higher recognition rate for Lamiaceae plants. Therefore, the employment of ITS2 as core with matK as supplement was able to identify Lamiaceae plants quickly and accurately, and understand the genetic relationship between species accurately. This provides an important theoretical basis for the effective protection and rational development of the medicinal plant resources of the Labiatae plants in Emei Mountain.