A MORPHOLOGY, ANATOMY AND GENETIC CHARACTERIZATION OF SOME THYME CULTIVARS FROM THE NIKITA BOTANICAL GARDEN COLLECTION

In the research works of various fields, including food industry and medicine, a great attention is paid to the medicinal and aromatic plants of the families Myrtaceae Juss., Lauraceae Juss. and Lamiaceae Martinov. Thymus L. is one of the most important genera of the Lamiaceae family, with aromatic and medicinal properties, it is one of the most popular plants with an essential oil, one of the ten best ones in the world. In the Nikita Botanical Gardens (NBG) on the ex situ collection plots, besides the introduced plants, there are thyme cultivars of the NBG selection. For further plant usage, a cultivar comprehensive study is necessary. Therefore, the objective of the research was a comparative morphological, anatomical analysis, an essential oil amount determination and a genetic similarity evaluation. T. mastichina (L.) L. cv. Svetliachok, T. striatus Vahl. cv. Jubileiniy and T. vulgaris L. cv. Fantazia (NBG selection) were used. The leaf morphology was studied under the stereomicroscope, the organ sections were obtained on a freezing microtome, stained with methylene blue and examined under a light microscope, an essential oil was extracted using Ginsberg devices, DNAs were isolated with CTAB-method, genetic similarity was evaluated with RAPD-PCR on the basis of binary matrices in the PAST program. A comparative morphological and anatomical analysis of the cultivars revealed the common structure of vegetative and generative organs. The differences were established in the stem color, the leaf blade sizes, the type of mechanical tissue under midrib, the area of inclusions with essential oil and its total amount. The analysis of a genetic similarity showed that T. mastichina cv. Svetliachok formed a separate cluster, cultivars of T. striatus (Jubileiniy) and T. vulgaris (Fantazia) were closer.