Medicinal plants are important objects for botany, systematics and plant geography research, as well as physiology, pharmacology, and biotechnology. Medicinal plants from the Lamiaceae family are being intensively studied for medical and pharmacological reasons. This family also includes the medicinal herbaceous plant oregano (Origanum vulgare L.), known from ancient times for its antimicrobial and antifungal properties, the ability to strengthen the human immune system, and to improve the general state of an organism. At present, the study of its antimicrobial, antifungal, insecticidal, anticoagulant, antitumor, therapeutic and many other properties is being actively continued. Due to the relevance of the development of the principles of O. vulgare micropropagation in vitro and the undeveloped conditions and methods of its cultivation, the aim of this work was to optimize microclonation in vitro of oregano via the activation of auxiliary buds. The research tasks were to test the ability of auxiliary buds to be activated depending on the localization on the donor shoot internodes and to intensify the root formation of cuttings through medium content optimization. The influence of the location of the auxiliary buds on donor shoots on their activation in vitro was studied on such indicators as the length of newly formed shoots, the number of nodules per one newly formed shoot, and the number of newly formed shoots per one bud. In plant microclonal propagation, the stage of root formation is very important for further adaptation in soil. Practical experience has shown that for the effective adaptation of oregano in soil, the length of the root system for cuttings should be 1.5–2.0 cm, the degree of root system development – 4–5 points under shoot length of 3–5 cm. The study of peculiarities of oregano microclonal propagation via activation of auxiliary buds has allowed us to optimize the stage of explant selection for cutting and the formation of cuttings’ roots. It has been established that for optimal length, the number of nodules of the newly formed shoots and the number of newly formed shoots, the first internode, located on the top of a parent shoot, as well as the third to fifth ones are more suitable. For rooting oregano cuttings, the optimal medium on the ratio of length and density of root system and on shoot length is the nutrient one containing half of the macro-, microsalts and vitamins on Murashige-Skoog, 20 g/l sucrose and 0.75 mg/l kinetin.
Effect of Organic Fertilization on Growth and Development of the Root System of two Medicinal Plants, oregano (Origanum vulgare L.) and milk thistle (Silybum marianum L. Gaertn.)
