IN VITRO CELL CULTURES OF GINKGO BILOBA L., INTRODUCED IN THE MOSCOW REGION ARE PROMISING SOURCES OF SUBSTANCES WITH HIGH BIOLOGICAL ACTIVITY

Intoduction. Ginkgo biloba (L.) are relict plants characterized by a limited area of growth, the valuable biomass of which is able to accumulate unique secondary metabolites that do not have synthetic analogues. Based on extracts of the leaves of ginkgo biloba, which have a nootropic effect. biologically active additives and medicines are produced – Tanakan, Bilobil, Ginkor gel, etc.. Plants of the genus Ginkgo grow in specialized microecological niches that limit their natural distribution area. It is known that biotic stress is one of the main environmental factors limiting the introduction of valuable plant species – possible sources of production of unique metabolites. Limiting environmental factors have a direct impact on the growth, development and productivity of secondary plant metabolism. Stress-resistant and highly productive plants can be created using cell biotechnology methods, in particular, in vitro cell selection, which is carried out on a callus culture. Therefore, at the first stage, it is necessary to develop in vitro technology for the rapid production of well-proliferating callus tissue with an increased content of secondary metabolites. Purpose of the study. To study the effect of the vegetation and photoperiod, endogenous polyphenols on the formation of the callus tissue of sequoia (Ginkgo biloba (L.)) in vitro. Material and methods. The object of the study was Ginkgo biloba (L.) plants. Callus tissue was obtained from segments of leaf blades that were isolated from intact plants. Explants were cultured on WPM nutrient medium containing BAP 2.0 mg/l and 2.0 mg/L 2,4-D. The localization of phenolic compounds was studied in Ginkgo leaves, as well as in callus tissue obtained under different lighting conditions. To do this, histochemical methods were used: for the sum of phenolic compounds, the material was stained with 0.08% Fast Blue reagent raster, a reaction with vanillin reagent in hydrochloric acid vapor was used to study the localization of flavans (catechins and proanthocyanidins). Results. The intensity of callus tissue formation, its consistency and color were significantly influenced by the growing season and the applied lighting regime. A well-proliferating callus tissue of light yellow color was obtained by cultivation with no light source. At a 16-hour photoperiod, a dark brown callus tissue with green inclusions was formed, the growth of which was inhibited during cultivation. Explants collected in spring and summer had the best proliferative activity. As a rule, the formation of callus tissue occurred in places of minor localization of phenolic compounds. In initiated callus cultures grown in the dark, the content of cells with phenolic compounds was lower than that of callus obtained in the presence of lighting. Extracts of G. biloba L. callus cultures they exhibit low cytotoxicity and can be widely used as a safe raw material for phytopharmacognosy.