THE EFFECT OF THE HORMONAL COMPOSITION OF THE NUTRIENT MEDIUM AND ENDOGENOUS POLYPHENOLS ON THE FORMATION OF CALLUS TISSUE IPOMOEA BATATAS (L.)

Relevance. Ipomoea batatas (L.) is a valuable agricultural crop, in the tubers of which inulin accumulates, a natural polysaccharide that has no synthetic analogues. Market analysis shows that, as a rule, in the production of functional food products, Russian manufacturers use imported inulin. Currently, globalization, the information revolution, as well as the sanctions policy have exacerbated significant problems of the world economy, which increases the relevance of import substitution of a number of goods and products. It is known that cold stress is one of the main environmental factors limiting agricultural production. Low positive temperatures have a negative impact on the growth, development, productivity and yield of I. batatas (L.) plants. It is possible to create such plants using cell biotechnology methods, in particular, in vitro cell selection, which is carried out on a callus culture. Purpose of the study. To study the effect of the hormonal composition of the nutrient medium and endogenous polyphenols on the formation of the callus tissue of sweet potatoes (I. batatas (L.)) in vitro. Material and methods. The object of the study were three varieties of I. batatas (L.) (Purple, Jewel, Porto Rico). Callus tissue was obtained from segments of leaf blades and stem internodes, which were isolated from aseptic sweet potato plants. Explants were cultured on MS nutrient medium containing BAP 0.5 mg/l and 1 mg/l NAA/IAA/2,4-D. The localization of phenolic compounds was studied in leaves, stems, and apical buds of microclones. In addition, localization was studied in the callus tissue obtained on different auxins. Histochemical methods were used for this. For the amount of phenolic compounds, the material was stained with 0.08% Fast Blue reagent raster. To study the localization of flavans (catechins and proanthocyanidins), a reaction with a vanillin reagent in hydrochloric acid vapors was used. Results. It was found that the auxins used had a significant effect on the intensity of callus tissue formation, its consistency and color. A well-proliferating callus tissue of light yellow color was obtained on a medium with NAA, a dense, green rhizogenic callus tissue was formed on a medium with IAA, and a dark brown tissue was formed on a medium with 2,4-D, which died during cultivation. As a rule, callus tissue was formed in those places where the formation and localization of phenolic compounds was insignificant. Conclusion. It was found that in callus cultures initiated from leaf plates and grown on a nutrient medium with NAA, the content of cells with phenolic compounds was less than that of callus obtained from leaf plates as well, but on a medium with 2,4-D.