EVALUATION OF THE DNA BARCODING APPROACH IN HYPERICUM SPP. DISCRIMINATION

Abstract

Hypericum, with more than 450 species, is widespread in temperate zones all over the world. In Italy 30 taxa are known (1), 26 species and 4 subspecies; ten of them are native to Sicily, in addition to H. calycinum which is recoded as naturalized. Hypericum biochemical compounds (flavanols, flavonoids, cumarins, glicosidys, terpens, tannins, essential oils) are well recognized for many pharmacological activities: antiflogistic, improving blood flow, against traumas, in wounds and burns recovering. The most important activity is ascribed to the hipericyn, a compound especially derived from Hypericum perforatum L., with successfully application in anti-depressive phytotherapy. The medical relevance and the related commercial interest push for improving the taxonomic identification method to dispose of certain plant material. Methods for fast and accurate identification of plant species are required to support morphological characterization. In this study the potential of the “DNA Barcoding” molecular method was investigated in discriminating the Italian Hypericum taxa in order to develop an easy authentication assay helpful in solving taxonomic doubts or in commercial trade traceability of whole plants, portions or derived products. The samples range was mainly recovered from native habitats in Italy, during the flowering period. Some samples were also sourced from certified herbarium collection. The DNA extraction was carried in three biological replicates, according to CTAB protocol for plant material (2). The DNA bank and also the ex-situ collection are stored at CRA-SFM of Bagheria. The three plastid regions, rbcL, matK and trnH-psbA, were assessed, according to the CBOL Plant Working Group indications (3). Phylogenetic analysis of each molecular marker were conducted by comparing sequences including those available from international databases (BOLD/NCBI) based on Kimura 2-parameter (4). The preliminary results indicate the effectiveness of this method in discriminating the taxa of Hypericum, suggesting the possibility to build a fast and accurate molecular identification method by barcode.