CURRENT PERSPECTIVES AND EMERGING TRENDS IN PCR-BASED DNA BARCODING FOR MOLECULAR IDENTIFICATION OF PLANTS: PROGRESS, CHALLENGES, AND FUTURE PROSPECTS

Dr. R. Sundhararajan1, M. J. Parimala*2, E. Mohamed Nizarudeen3, S. Mohamed Shahid Akeel4, S. Mohamed Shahul Hameed5, B. Mohamed Siddiq6

DNA barcoding is an efficient approach for categorization and identification of plant species using genomic sequences. It is straightforward, time- and cost-efficient, and accurate. The key to successful DNA barcoding is the selection of an appropriate DNA marker. Since the concept of rapid species identification was introduced in 2003, the scientific community has recognized the potential of DNA barcodes. DNA barcoding has applications in preserving natural resources, protecting endangered species, controlling agricultural pests, identifying disease vectors, monitoring water quality, authenticating natural health products, and identifying medicinal plants. Detailed analysis is performed using amplified sequences of rbcL, ITS2, matK, psbA-trnH, rpoC1, and other markers, with databases such as GenBank, the National Center for Biotechnology Information (NCBI), and the Barcode of Life Data System (BOLD). DNA barcoding can efficiently detect adulteration by identifying unknown species against known database sequences. Analytical techniques such as HPLC-MS, HPLC-UV, and GC can be combined with DNA barcoding to quantify key compounds in herbal medicines responsible for pharmacological effects. Different barcode approaches, including single-locus, multi-locus, metabarcoding, mini-barcoding, and bar-HRM analysis, have various strengths and limitations. DNA barcoding plays a major role in addressing herbal medicine adulteration through species identification, detection of adulterants in raw or processed herbal medicines, database development, research, and surveillance. This review highlights progress in plant taxonomy, the success of barcode loci, the emergence of super barcodes from chloroplast genomes, and the impact of next-generation sequencing technologies.