Comparison of the phytochemical content of St. John's wort (Hypericum perforatum L.) grown in externel and In vitro conditions

St. John's Wort (Hypericum perforatum L.) is an important medicinal aromatic plant used in the pharmaceutical field with its high phytochemical content. Within the scope of this study; In vitro conditions, using the leaf and node parts of the St. John's wort plant, firstly, determining the appropriate sterilization method, performing shoot and callus regenerations from sterile explants, and then comparing the phytochemical content of the plants grown in in vitro conditions with the plants under external conditions. In the study, two different sterilization methods were tried in both explant types. The highest sterilization success was achieved by standing in 70 % (v/v) ethyl alcohol for 1 minute after prewash, and then for 3 minutes in 35 % (v/v) blech solution. 100 % sterilization success was achieved in both types of explants. Six different media containing different concentrations of BAP and NAA were used to establish in vitro shoot cultures. The best shoot growth percentage and number of shoots per explant were obtained in MS nutrient media supplemented with 0,5 mg / L BAP and 2,5 mg / L NAA. 100% shoot development for leaf explant and the number of shoots per explant was found to be 5,53. For the node explant, 80% shoot growth was observed, while the number of shoots per explant was 4,33. Four different medias were used to establish callus cultures. The highest wet and dry weight was obtained in an media where MS nutrient medium supplemented with 1,0 mg / L NAA was used. In the continuation of the study, the phytochemical contents of external conditions plants and in vitro shoots and developing calluses were compared in terms of volatile components. The most found component was cis-Osimen (13.62%) in plants grown in external conditions. In vitro shoots, 1- [3-methyl-3- (4-methyl-3-pentenyl) oxiranyl] - Ethanone (22,63%) has been detected as most found component and Nerolidol Z and E (% 19,96) component was found as terpene. The most found component in callus was 1,3,5-Cycloheptatriene (12,14%), while Farnesane (7,94%) was the most common terpene component. When evaluated in terms of terpene derivative compounds, which are the most valuable group for volatile components, values of 40,84% in external plants, 35,36% for in vitro shoots and 29,39% in calluses were obtained. This study will contribute to the literature and shed light on the establishment of cell suspension cultures that are the continuation of the study. It will be a source of research planned on a special active ingredient by optimizing in vitro studies.