One of the methods of obtaining planting material for deciduous woody plants, in particular, common ash (Fraxinus excelsior L.), large-leaved linden (Tilia platyphyllos Scop.), and the silver birch (Betula pendula Roth) is micropropagation. Explant asepsis – prerequisite for microclonal plant reproduction. For the most part, chemical sterilisation with liquid substances is used for this purpose. The decontamination regime is influenced by a number of factors, in particular, the genotype of the plant. The purpose of the study is to optimise the explant sterilisation protocol of F. excelsior, T. platyphyllos, and B. pendula for micropropagation. For the study, 20-30 cm parts of shoots isolated from a 12-year-old T. platyphyllos, 10-yearold B. pendula, and a 15-year-old F. excelsior were used in February-March 2021 Plant material was cultured according to the generally accepted method on an MS nutrient medium (Murashige & Skoog, 1962). MS Excel software tools were used to process the research data, the average, and its main error were calculated. Univariate analysis of variance (ANOVA) was performed to analyse the effect of explant sterilisation mode on asepsis. The expediency of keeping plant material for a day in fungicidal preparations, in particular, in 0.1% “Samshit” solution, is shown – F. excelsior and 0.3% Fundazol solution – T. platyphyllos and B. pendula. The protocol of sterilisation of experimental plants (efficiency over 50%) is optimised by using a step method using 70% ethyl alcohol, 1.0% and 2.0% AgNO3, and 2.5% and 5.0% NaClO. It was identified that the effect of the sterilisation regime of experimental plants on asepsis is statistically substantial at the level of 5%. A MS nutrient medium with the addition of 0.25 mg*l-1 kinetin and 2.0 g*l-1 activated carbon was used to initiate explants. Further research is aimed at developing a protocol for the direct regeneration of plant microshoots of F. excelsior, T. platyphyllos, and B. pendula by the action of the components of the nutrient medium in vitro
in vitro plant tissue culture, Fraxinus excelsior L., Tilia platyphyllos Scop., Betula pendula Roth, sterilization, explants, regenerative ability, culture medium, microclonal propagation