rbcL, a potential candidate DNA barcode loci for aconites: conservation of himalayan aconites

Aconitum heterophyllum Wall. ex Royle and Aconitum balfourii Stapf, are two highly important, threatened medicinal plants of the Indian Himalayan Region. Root-tubers of Aconites have occupied an important place in Indian pharmacopoeia from very ancient times. India is a hub of the wild-collected medicinal herbs industry in Asia and these two aconites are known to have been heavily traded from the region in illicit manner. Prosecution of these illegal trading crimes is hampered by lack of pharma-forensic expertise and tools.

Present study was conducted to evaluate the discriminatory potential of rbcL, a Chloroplast based DNA barcode marker for the authentication of these two Himalayan Aconites. Fresh plant samples were collected from their natural distributional range as well as raw materials were procured from herbal market and a total of 32 sequences were generated for the rbcL region. Analysis demonstrated that rbcL region can successfully be used for authentication and importantly, both the aconites, were successfully discriminated by rbcL locus with high bootstrap support (> 50%).

Molecular markers could certainly be relied upon morphological and chemical markers being tissue specific, having a higher discriminatory power and not age dependent. Phylogenetic analysis using Maximum Likelihood Method revealed that the rbcL gene could successfully discriminate Himalayan Aconites to species level and have potential to be used in pharma-forensic applications as well as to curb illicit trade of these invaluable medicinal plants.