DNA Barcoding of St. John's wort (Hypericum spp.) Growing Wild in North-Eastern Greece.

Plants of the genus , commonly known as "St. John's wort" ("spathohorto" or "valsamo" in Greek), have been used since antiquity for their therapeutic properties. Wild-harvested plants are still popular today in herbal medicines, commercially exploited due to their bioactive compounds, hypericin and hyperforin, which have antidepressant, antimicrobial and antiviral activity. Species identification of commercial products is therefore important and DNA barcoding, a molecular method that uses small sequences of organisms' genome as barcodes, can be useful in this direction. In this study, we collected plants of the genus that grow wild in North-Eastern Greece and explored the efficiency of , and regions as DNA barcodes for their identification. We focused on 5 taxa, namely subsp. , and the latter a rare Balkan endemic species collected for the first time from mainland Greece. (using the genus-specific primers designed herein), , and their combination were effectively used for the identification of the 5 taxa and the discrimination of different subsp. populations. These barcodes were also able to discriminate Greek populations of , and from populations of the same species growing in other countries.