DNA barcoding provides distinction between Radix Astragali and its adulterants

Area of Science:

• Molecular Biology
• Botany
• Pharmacognosy

Background:

• DNA barcoding is vital for species identification, biodiversity, forensics, and medicinal plant authentication.
• Radix Astragali (Astragalus membranaceus and A. membranaceus var. mongholica) is frequently adulterated with 23 other species from related genera.
• Accurate methods are needed to differentiate authentic Radix Astragali from adulterants.

Purpose of the Study:

• To evaluate four DNA barcoding markers (ITS, matK, rbcL, coxI) for distinguishing Radix Astragali from adulterants.
• To identify the most effective markers for species identification within the Fabaceae family.

Main Methods:

• Sequencing of ITS, matK, rbcL, and coxI from 37 samples across four Fabaceae genera.
• Analysis of genetic variation at intergenic, interspecific, and intraspecific levels.
• Identification of specific sequence variations, including indels, for discrimination.

Main Results:

• ITS showed high divergence at generic (4.5%) and interspecific (14.1%) levels.
• matK demonstrated sufficient divergence for intraspecific identification.
• Two indels in matK were identified as useful markers for distinguishing Radix Astragali from adulterants.

Conclusions:

• The combined ITS and matK regions represent superior DNA barcodes for Radix Astragali authentication.
• These markers provide a reliable method for distinguishing authentic medicinal herbs from adulterants.
• Further research should validate these combined markers for broader application in traditional Chinese medicine quality control.