PECULIARITIES OF <i>THYMUSVULGARIS</i> L. EXPLANTS MORPHOGENESIS AT THE FIRST STAGE OF CLONAL MICROPROPAGATION
The aim of the study was to obtain an aseptic culture in vitro and to study the effect of explant type and culture medium composition on the explant morphogenesis at the first stage of clonal micropropagation of Thymus vulgaris. The shoot tips and stem segments with a node (8 - 10 mm) were introduced into an isolated culture.Research findings on sterilization and cultivation explants on 12 modifications of Murashige and Skoog culture medium are presented in the article. It was found that sequential sterilization with 70 % ethanol (40 sec) and 0.3 % solution of DesTab (3 min) allowed obtaining the maximum amount of sterile (94.2 %) and viable (90.5 %) explants. When studying the influence of the culture medium hormonal composition on the morphometric parameters of explants, the best development of the explants was revealed on medium containing Kinetin, as compared with BAP and TDZ.It was found that the optimal composition of culture medium at the introduction stage is the MS medium with 1.0 mg/l of Kinetin and 1.0 mg/l of GА<sub>3</sub>, at which microshoots 1.7 - 2.0 cm long with 2.2 - 2.9 nodes were obtained.Analysis of the effect of explant type showed that from the shoot tips, compared to stem segments with a node, longer microshoots with a greater number of nodes developed on most culture media.However, the number of shoots formed from the explants of the shoot tips was less than from the segments of the stem. The results of the studies are the basis for development of the T. vulgaris clonal micropropagation methods.