The Impact of the Growth Regulators and Cultivation Conditions of Temporary Immersion Systems (TISs) on the Morphological Characteristics of Potato Explants and Microtubers

Potatoes (Solanum tuberosum L.) constitute one of the most economically important annual crops. In terms of tissue culture, potato microtubers (MTs) have a number of advantages over conventional plants. These advantages include their small size, which greatly facilitates storage, transport, and germplasm exchange compared to in vitro plants. One effective solution for the production and mass propagation of healthy MTs is the use of temporary immersion systems (TISs). In this study, in a SETISTM system containing kinetin/gibberellic acid (GA)/indole-3-butyric acid (IBA) hormones, we investigated the effects of different nutrient media on the morphological characteristics of potato explants and MTs. We determined the optimal cycling duration (3 h) with an immersion frequency of 2 min. The results revealed that the optimal nutrient medium for culturing single-node potato explants in a SETISTM bioreactor was the M7 medium containing kinetin (2 mg/L), GA (0.5 mg/L), and IBA (0.5 mg/L). The optimal nutrient medium for obtaining potato MTs was the M1 medium (hormone-free) with a high concentration of sucrose (9%) at 18 °C under dark growing conditions. Thus, a universal nutrient medium, employed in a bioreactor, was selected for the mass propagation of potato MTs for both domestic and foreign potato varieties.