Hormonal status of stolons and formed tubers during the vegetation of potato plants (Solanum tuberosum L.)

The content of four groups of phytohormones – auxins, cytokinins, abscisic acid – was studied by the method of solid-phase enzyme immunoassay and gibberellins by the method of biotesting in stolons and forming tubers during the vegetation period of Solanum tuberosum grown in soil culture under vegetation conditions. The prevalence of gibberellins was revealed during the period of stolon growth. At the beginning of tuber formation initiation, ABA increases, which can contribute to the cessation of stolon growth, but the content of IAA and zeatin remains high. Stolons of large tubers contained more GA₃, IAA, but less ABA, had a greater number of vessels in the vascular bundle. The prevalence of auxins and a decrease in the ABA content in large tubers compared to small ones were established. An increase in the mass of large tubers in a bush, as well as the thickness of their phellem (cork), the diameter of the cells of the perimedullary zone and the size of the cells of the cortex, compared to small tubers, was shown against the background of a higher IAA/ABA ratio.