Characterization of Origanum glandulosum Desf. Essential Oils Collected from Different Culture Conditions Towards Standardized ex situ Production

Abstract

Medicinal plants have always drawn interest in scientific research as well as industry, particularly, pharmaceutical and agri-food industries. With a view to preserving and sustainably exploiting local biological resources, the main objective of this study was the establishment of an optimized biotechnological process for the production of Origanum glandulosum essential oils (EOs) involving in vitro culture and acclimatization conditions of micro propagated vitro plants (O. glandulosum plants obtained and multiplied in vitro). After plant material disinfection, in vitro plant micropropagation was made using oregano nodal fragments on MS media with different hormonal balances (BAP: 0, 0.25 and 0.5 mg/L, IAA: 0, 0.25 and 1 mg/L and GA3: 0 and 0.5 mg/L). Vitro plants with well-developed roots were acclimatized in three different culture conditions (AC1, AC2 and AC3). The chemical composition and biological activities of EOs extracted by hydrodistillation were the parameters of the choice for the standardized production process. The results of the study enabled the establishment of a production process after 70 days of oregano vitro plants acclimatization in the conditions of 70 % humidity, 18°C with 12-h light photoperiod 1st week, 20°C with 14-h light photoperiod 2ndweek, 22°C 16-h light 3rdweek and 24°C with 16-h light photoperiod for the last 7 weeks. In these conditions, the produced essential oil is with an extraction yield of 1.48 mL/100 g D.W., with thymol-chemotype (28 %) and similar biological activities to that of essential oil extracted from wild plants.