Ribosomal DNA-ITS sequence analysis and molecular identification of Morinda officinalis and its counterfeit species / 中草药

ABSTRACT

Objective To compare the rDNA-ITS differentiation and its regulation between Morinda (officinalis) and its counterfeit species, and provide DNA molecular markers for the fingerprint identification of them. Methods The rDNA-ITS regions of M. officinalis and its counterfeit species were amplified and sequenced, then analyzed by means of CLUSTRAL X and MEGA softwares. Results The internal transcribed spacers (ITS) including ITS1, 5.8S, ITS2, and partial 18S and 26S were determined. In DNA DIST analysis, the range of diversity among M. officinalis and M. shughuaeusis, M. umbellata was (2.9%-)5.8% and 2.9%-4.2% based on ITS1 and ITS2; the range of diversity between M. officinalis and Damnacanthus indicus was 21.2% and 18.9% based on ITS1 and ITS2. Phylogenetic tree based on ITS and 5.8S sequence data indicated the M. umbellata and M. shuanghuaensis were closely related then with M. officinalis, while D. indicus was monophyletic group. Conclusion The rDNA-ITS sequence is a better molecular marker for idertification of M. officinalis and its counterfeit species.