Influence of Growth Regulators on Micropropagation System of Medicinal Plant Yacon (Smallanthus sonchifolius (Poepp.) H. Rob.)

ABSTRACT

Background and Objective: Currently, an interest in the cultivation of yacon is growing, which is a plant with strong medical potential. Therefore, studies on the optimization of the yacon micropropagation method in tissue cultures were undertaken. Materials and Methods: Reproduction of this plant is conducted with the use of traditional methods by green seedlings or 8-12 cm long offsets (‘seeds’) taken from the underground and aboveground rootstock (‘crown’). The influence of different disinfection methods, various initial explants and growth regulators, also their concentrations on the efficiency of micropropagation protocol in conducted research was analyzed. Results: The most effective disinfection was the application of 70% ethanol and 0.5% Tween 20. The optimal initial explants in the current research were apical and lateral buds cultured on MS medium supplemented with 0.2 mg L^-1 kinetin and 1 mg L^-1 indole-3-acetic acid. The most intensive shoot regeneration occurred on MS media with the addition of 1 mg L^-1thidiazuron and 1-naphthylacetic acid. Histological observations demonstrated the strong effect of these growth substances on shoots organogenesis from callus tissue. Conclusion: Shoots obtained from in vitro cultures rooted easily on modified MS media with ½ or ¼ concentration of macroelements, 20 g L^-1 sucrose and 3 mg L^-1 1-naphthylacetic acid and then adapted to ex vitro conditions in 100%.