Synthetic growth regulators: role in microclonal reproduction of medicinal plants Dioscorea nipponica Makino, formation and localization of polyphenols

Relevance of work. Thanks to clonal micro-reproduction, it became possible to preserve endangered medicinal plants by genetic banks in vitro. Obtained in the shortest possible time regenerative plants, genetically identical to the original intact plant, can be considered as potential sources of secondary metabolites-valuable biologically active substances widely used in the pharmaceutical industry. The aim of our study was to study the effect of the hormonal composition of the nutrient medium on the microclonal reproduction of plants Dioscorea nipponica Makino, as well as on the formation and localization of phenolic compounds in plant regenerants multiplied in vitro. Material and Methods. The object of the study was intact plants Dioscorea nipponica Makino and microclones derived from them. For the induction of the formation of axillary shoots, adventitious buds and microtubers primary explants were cultured on a nutrient medium containing mineral salts according to the recipe of Murashige and Skoog and various substances with cytokinin and auxin activity at a temperature of 24 С and 16-hour photoperiod. For rooting micropolygon used a modified containing Ъ norms macrosoma, 20 g/l sucrose, 7 g/l agar and IAA at a concentration of 1 mg/L. Adaptation of plants held in containers containing proantocianidinas substrate. The content of soluble phenolic compounds (with Folin-Denis reagent), flavans (with vanillin reagent) and flavonols (with aluminum chloride) was determined by spectrophotometric method in alcohol plant extracts. Localization of polyphenols was determined by histochemical methods (0.08% fast Blue reagent raster, reaction with vanillin reagent in hydrochloric acid vapor). Results. The resulting microclone medicinal plants with a high biosynthetic capacity to the formation of polyphenols (flavanol and fla-vanols), was characterized by intense growth, the formation of a powerful biomass and adventitious roots. Flavans were major components of the phenolic complex of regenerating plants. The species-specific ability to synthesize phenolic compounds is preserved in vitro. And in the education of bioflavonoids observed organospecificity, which, in a less pronounced degree, is preserved in vitro. It was revealed that the intensity of staining of tissues of microclones was slightly lower, which is consistent with the data on the quantitative content of polyphenols in them. Synthetic growth regulators with cytokinin activity (especially the drug Dropp), have a bright stimulating effect not only on the process of clonal micropropagation, but also on the biosynthetic activity against substances of phenolic nature. Biochemical data are confirmed by histochemical studies.

phenolic compounds, flavanes, flavanols, localization, Microclones, Dioscorea nipponica Makino