DNA barcoding in plants: taxonomy in a new perspective

DNA barcoding is the process of identification of species based on nucleotide diversity of short DNA segments. It is well established in animals with the introduction of cytochrome c oxidase subunit 1 (COI) as a standard barcode. In plants, however, due to the difficulty in finding a universally acceptable barcode, it is yet to be well established. Based on the relative efficacy testing, the Consortium for the Barcode of Life–Plant Working Group has recently identified a few loci as potential barcode candidates and from them a two-locus standard barcode (rbcL + matK) has been recommended for initiating the barcoding process of plant species. With 70% species discriminatory power, this two-locus barcode is capable of serving many projects, but for better resolution additional loci need to be used. This article provides an overview of the technical details, and merits and demerits of these loci as plant barcodes.