University proceedings. Volga region. Natural sciences

Background. The content of phytohormones in potato tubers is mainly studied during their initiation and further growth. Meanwhile, it is of interest to study the dynamics of phytohormones not only in young tubers, but also in maternal (planting) tubers, since they are known to supply not only nutrients, but also phytohormones. However, the available information concerns the study of the content of only one or two groups of phytohormones before the initiation of tuber formation. In the subsequent period of plant vegetation, their hormonal status has not been studied. The purpose of this work was to study four groups of phytohormones (gibberellins, auxins, cytokinins, abscisic acid) in the maternal tuber, starting from its planting and ending 25 days after the flowering phase. At the same time, the intensity of the respiration process of these tubers was studied. Materials and methods. The object of the study were maternal tubers of the Skoroplodny potato variety. The plants were grown in soil culture in a vegetation house. The content of auxins, cytokinins, and abscisic acid was determined by solid-phase enzyme immunoassay. The content of gibberellic acid was determined by biotesting using Shustrik pea sprouts. IAA, zeatin, GA, and ABA were used as standard solutions. The respiration rate was determined by the amount of CO2 released in devices for monitoring gas exchange using the titration method. The reliability of the results was assessed using the Student's criterion. Results. The study revealed a 30 % decrease in gibberellic acid in the mother tuber 39 days after planting, and an almost twofold decrease between 15 days after emergence and budding. No GA content was detected after flowering. The content of IAA, unlike gibberellic acid, decreased gradually during plant vegetation. 25 days after flowering, it decreased by 38 % of the initial value. Against the background of a decrease in auxins and gibberellins, the intensity of respiration of the mother tuber decreased. Cytokinins (zeatin) were contained in an insignificant amount. Their level did not change during vegetation. The amount of ABA after flowering decreased by half. Conclusions. A conclusion is made about different degrees of mobilization of four groups of phytohormones from the mother tuber during the vegetation of potato plants.