Establishment of Efficient Protocol for Rapid and Massive Micropropagation of Greek oregano (Origanum heracleoticum L.)

Greek oregano (Origanum heracleoticum L, Lamiaceae) was used from ancient times in folk medicine. Presently is largely applied in pharmaceutical and food industry as a source of important biologically active substances with antioxidant and antimicrobial properties. The efficient and low-cost protocol for large-scale multiplication of this aromatic plant was developed using young stem tips explants. The explants were cultured on full and half strength Murashige and Skoog medium containing indole-3-butyric acid. Maximum shoot and root number were obtained on ½ Murashige and Skoog medium supplemented with 0.1 mg L-1 indole-3-butyric acid at the same time after four weeks of culture. The number of shoots per explant, shoot height, rooting percentage, the number of roots per plant and root length were collected and considered after the same cultural period. The highest percentage of survival 85% for this medicinal plant was recorded in a mixture of soil, sand and perlite (2:1:1 v/v/v). This substrate mixture was most suitable for acclimatization of all propagated plants. After the adaptation period, the plants were transferred to the field. The plants bloomed within three months after transplantation without any phenotypic variations. An average of 90% of the acclimatized plants survived after transferring into the field. All the plants displayed normal development under the field conditions. Developed in vitro techniques could provide a promising alternative tool for large-scale field cultivation of in vitro propagated homologous Origanum heracleoticum plants.

This study was conducted with financial support from National Science Fund at the Bulgarian Ministry of Education and Science, Project DN06/7 17.12.16.