Integrated analysis for identifying radix astragali and its adulterants based on DNA barcoding

Area of Science:

• Pharmacognosy
• Molecular Biology
• Genetics

Background:

• Radix Astragali is vital in traditional Chinese medicine for immune and antidiabetic effects.
• Distinguishing Radix Astragali from adulterants is challenging but essential for efficacy and safety.
• DNA barcoding is a powerful tool for plant identification, but requires optimization for specific applications.

Purpose of the Study:

• To validate an integrated DNA barcoding analysis method for distinguishing Radix Astragali from its adulterants.
• To evaluate the efficacy of six candidate DNA barcodes for species identification.
• To identify the optimal DNA barcode for reliable authentication of Radix Astragali.

Main Methods:

• Collected 478 DNA sequences from six candidate barcodes (ITS2, ITS, psbA-trnH, rbcL, matK, COI).
• Analyzed sequences from 29 species, including Radix Astragali and potential adulterants.
• Focused on genetic distance, identification efficiency, inter-/intraspecific variation, and barcoding gap.

Main Results:

• The internal transcribed spacer (ITS) sequence demonstrated the highest identification efficiency.
• ITS provided clear discrimination between Radix Astragali and its adulterants.
• The integrated analysis method effectively addressed limitations of traditional DNA barcoding approaches.

Conclusions:

• The internal transcribed spacer (ITS) is the optimal DNA barcode for identifying Radix Astragali and its adulterants.
• The validated integrated analysis method enhances the accuracy and utility of DNA barcoding in pharmacognosy.
• This approach facilitates reliable authentication and data mining for medicinal plant resources.