DNA barcoding: An effective molecular tool for species identification, molecular authentication and phylogeny studies in plant science research

DNA barcoding is a technique for identifying specimens using brief, standardised DNA segments. In a variety of fields, including phylogeny, ecology, population genetics and biodiversity, DNA barcoding has become a successful method for precisely distinguishing species. The method is straightforward, efficient in both time and money and accurate. The key to successful DNA barcoding is choosing the right DNA marker. Since the idea of a quick approach for species identification was first put up in 2003, the scientific community has been keen to realise the potential of DNA barcodes. Cytochrome c oxidase, I (COI) region of the mitochondrial genome is mostly recognised as a standard barcoding region in animals. Later, rbcL + matK pairing, with a 70 % discriminating efficiency, was suggested by the Plant Working Group (PWG) of the Consortium for the Barcoding of Life (CBOL) as the standard barcode in plants. Three conditions must be met for a gene region to be an efficient DNA barcode: it must have sufficient species-level genetic divergence and variability, it must have conserved flanking regions for the widest taxonomic use and for generating universal PCR primers and it should be long enough to facilitate current capability for sequencing and extracting DNA. Different combinations of plastid coding, non-coding and nuclear markers are utilised as supplemental markers to boost the degree of plant species differentiation. The reliability of different barcodes in distinguishing species varies among different groups of plants. As DNA barcoding approaches its twentieth anniversary, technologies are still being developed that make use of this resource, which is constantly expanding in a variety of biological disciplines. Plant DNA barcoding, which became a scientific advance during the last ten years, is frequently employed as a taxonomical aid in identifying species. It is a way of choosing genetic loci that identifies and distinguishes an organism's membership from specific species, variations or even intervarieties. It varies from molecular phylogeny, which identifies an unknown sample from an existing classification rather than identifying patterns of association.