Hebanthe paniculata (Martius) Kuntze and Pfaffia glomerata (Spreng) Pedersen, popularly known as "Brazilian Ginseng", are used as medicinal plants, but present difficulties in morphological proper identification, which can lead to the adulteration of the products. In addition to the fact that it is difficult to differentiate morphologically between these two species, for most of the time Brazilian Ginseng products are purchased processed and unlabelled or unpackaged. For this reason, identification of the species is done by using genetic material from Ginseng product samples (SUN et al., 2016).

Several DNA regions from the chloroplast genome showed sufficient variation to be useful in the identification of plant species. The matK gene region (maturation K) is one of the high-level discriminatory regions (CBOL, 2009). Analysis of this region is usually done by sequencing techniques, which is an expensive and laboratorial technique. Currently, however, the High Resolution Melting (HRM) technique has been proposed for polymorphism analysis because it is cheaper and faster.

The objective of this study was to evaluate if the HRM technique, using the matK gene region, is useful for the discrimination of the species H. paniculata and P. glomerata. For this, six samples were obtained, 3 of each of the mentioned species, and 50 commercial samples, sold as Brazilian Ginseng, through physical or online purchase. DNA was extracted by CTAB and Kit methods. The primer was tested by standard PCR amplification and confirmed on polyacrylamide gel prior to standardization of the amplification by PCR-HRM and finally the results were compared to those of the sequencing.

Results of the HRM race, using primers derived from the matK gene, presented discriminatory power for the two species with a Tm difference of approximately 0.5ºC. It was possible to notice that 88% of commercial samples amplified, and 11% of those did not correspond to the species written in their labels, characterizing adulteration of the products. Comparing the sequencing results with that of the HRM, 86% of the samples were also identified, 12% the HRM could not identify, and 2% the HRM identified and the sequencing did not. The method of authentication by the HRM technique allowed the discrimination between the species H. paniculata and P. glomerata, and the identification of adulteration of the samples commercialized as Brazilian Ginseng.