Abstract
European white elm (Ulmus laevis Pall.) tissue in vitro is a donor material for obtaining cultures with stable resistance to pathologies of infectious origin, namely to Dutch elm disease. To solve this problem, it is necessary to develop an effective protocol for the regeneration of U. laevis in vitro. The purpose of this study is to investigate the effect of chloramine concentrations on the mycobiota of U. laevis plant tissues for propagation in vitro. 10-15 cm parts of shoots from 25-year-old U. laevis were used as plant material. The study was conducted in the autumn of 2021. Microshoots previously sterilized with chloramine (1.0%, 2.5%, 5.0%, 10.0%) for 10 min were cultivated on a solid nutrient medium according to the WPM recipe (McCown & Lloyd, 1981) with the addition of 0.2 mg∙l -1 2 - iP (6-(γ,γ- Dimethylallylamino)purine) and 2.0 g∙l-1 of activated carbon. For microbiological analysis, sterilised plant material was cultured by accumulation in Petri dishes with a nutrient medium (sour potato agar) in a thermostat without lighting at +26 ± 1°C and a relative humidity of 68 ± 2%. Methods of biotechnological, mycological, and statistical research were employed in this study. Over 95% of the samples were found to be infected with microscopic fungi of the genus Mucor Fresen., Penicillium Link, Chaetomium Kunze and Trichoderma Pers. The effect of preparation concentration on the total number of infected explants is statistically insignificant at 5%. It was found that 5.0% preparation is effective for neutralising mycobiota of the genus Chaetomium and Trichoderma; 10.0% – for neutralising Penicillium mycobiota. If the concentration of chloramine increases, the intensity of infection of explants with mycobiota of various genera decreases. As a result of the research, a small amount of aseptic cultures were obtained from the shoots of U. laevis isolated in autumn. This study is relevant for biologists, biotechnologists, microbiologists, and biological scientists