INTERNAL TRANSCRIBED SPACER (ITS), AN IDEAL DNA BARCODE FOR SPECIES DISCRIMINATION IN CRAWFURDIA WALL. (GENTIANACEAE).

Background: DNA barcoding is a technique used to identify species based on species-specific differences in short regions of their DNA. It is widely used in species discrimination of medicinal plants and traditional medicines.

Materials And Methods: In the present study, four potential DNA barcodes, namely , , and ITS (nuclear ribosomal internal transcribed spacer) were adopted for species discrimination in Wall (Genetiaceae). Identification ability of these DNA barcodes and combinations were evaluated using three classic methods (Distance, Blast and Tree-Building).

Results: As a result, ITS, and regions showed great universality for a success rate of 100%; whereas matK was disappointing for which only 65% samples gained useful DNA sequences. ITS region, which could clearly and effectively identify the five species in , performed very well in this study. On the contrary, and performed poorly in discrimination among these species.

Conclusion: ITS marker was an ideal DNA barcode in and it should be incorporated into one of the core barcodes for seed plants.