Effect of BAP on total hypericin production in shoot cultures of Hypericum scabroides: An endemic species in the Eastern Anatolia region of Turkey

Background: Due to the therapeutic importance of hypericin, a number of Hypericum species are being investigated. The aim of this study was to determine the effect of various BAP (6- benzylaminopurine) concentrations on seed germination, shoot proliferation, and total hypericin in a tissue culture of Hypericum scabroides which is endemic to the Eastern Anatolia region, Turkey. Material and Methods: Hypericum scabroides specimens were collected from Eastern Anatolia (Elazig, Turkey). The effects of various BAP concentrations (0.0 (control), 0.5, 1.0, and 2.0 mg/L) on seed germination, shoot multiplication, and the accumulation of total hypericin were determined using tissue cultures of H. scabroides. Murashige and Skoog (MS) medium was used for germination and shoot cultures. Measurements of total hypericin were taken using a UV spectrophotometer. Results: The best germination rate (59.2%) was obtained using hormone-free MS medium (control group). Apical tips of freshly germinated seedlings were proliferated on the MS medium supplemented with various BAP concentrations (0.5, 1.0, and 2.0 mg/L) and the control group (without BAP). The highest number of shoots (42.7 shoot/explant) and longest shoot length (2.50 cm) were obtained on MS medium supplemented with 2.0 mg/L BAP. Total hypericin was found in trace amounts and it was found that the total hypericin was not affected by the concentration of BAP. Conclusions: Our results showed that increasing concentrations of BAP stimulated shoot multiplication but did not affect seed germination rates or total hypericin in in vitro cultures of H. scabroides.