Invasive plants have damaging effects on the biodiversity and therefore, development of quick and accurate identification method needs immediate attention. DNA barcoding technology offer several advantages in this regard such as quick identification of samples to species level, requirement of little amount of sample and no stringent requirement of floral characters.
The present work evaluates the utility of four molecular markers; rbcL, matK, their combination (rbcL + matK), and psbA-trnH for identification of 50 invasive plant species from India and also in distinguishing them from 100 native species. A psbA-trnH locus was found to be of restricted utility in this work as it was represented by the members of only one family Poaceae. A hierarchical increase in K2P mean divergence across different taxonomic levels was found to be the maximum for matK alone followed by (rbcL + matK) and rbcL alone, respectively. NJ clustering analysis, however, confirmed the suitability of combined locus (rbcL + matK) as the DNA barcode over individual rbcL and matK . RbcL alone showed the lowest resolution power, on the contrary, matK alone could identify most of the species accurately but it failed to show monophyly of genus Dinebra. A combined locus (rbcL + matK) was found to be the most suitable marker as it raised the resolution power of both the markers and could identify more than 90% of genera correctly. Phylogenetic tree constructed by Maximum-Parsimony method exhibited the best resolution, thus, supporting the significance of two-locus combination for barcoding invasive plant species. [1].