[DNA barcoding identification between arisaematis rhizoma and its adulterants based on ITS2 sequences]

Area of Science:

• Molecular Biology
• Botany
• Pharmacognosy

Background:

• Arisaematis Rhizoma is a valuable traditional Chinese medicine.
• Accurate identification is crucial to prevent adulteration with similar-looking species.
• Traditional identification methods can be unreliable.

Purpose of the Study:

• To evaluate the efficacy of the ITS2 (Internal Transcribed Spacer 2) region as a DNA barcode for Arisaematis Rhizoma identification.
• To differentiate genuine Arisaematis Rhizoma from its adulterants.
• To assess the potential of DNA barcoding in traditional Chinese medicine authentication.

Main Methods:

• Collected 58 samples from 7 species of Arisaematis Rhizoma and its adulterants.
• Amplified, sequenced, and assembled the ITS2 locus for DNA barcoding.
• Annotated ITS2 sequences using a Hidden Markov Model (HMM)-based method and analyzed intra- and inter-specific variations.

Main Results:

• Calculated inter-specific genetic distances (K2P) were significantly larger than intra-specific distances for key Arisaematis Rhizoma species.
• Phylogenetic analysis using Neighbor-Joining (NJ) tree construction showed distinct clustering of the three main origin species (Arisaema amurense, A. erubescens, A. heterophyllum) with high bootstrap support.
• The ITS2 DNA barcode demonstrated clear separation between Arisaematis Rhizoma and its adulterants.

Conclusions:

• The ITS2 locus is a reliable DNA barcode for the accurate identification of Arisaematis Rhizoma.
• This molecular approach effectively distinguishes genuine Arisaematis Rhizoma from commonly used adulterants.
• DNA barcoding using ITS2 holds significant potential for the authentication of traditional Chinese medicines.