EXPLANT STERILIZATION AND IN VITRO CULTURE OF PURPLE SWEET POTATO TO OPTIMIZE NORMAL SHOOT FORMATION

Abstract

Sweet potato (Ipomoea batatas L.), a tuber-producing plant, is a functional food that produces carbohydrates while meeting nutritional needs. Propagation of sweet potato through tissue culture is often hampered in the initial culture due to contamination. The study aimed to optimize sterilization of explants and growth of in vitro culture of purple sweet potato. Tubers of purple sweet potato cv. Antin 2 were ex vitro cultured through a semi-immersion system to produce shoots. The shoots as explants were sterilized with alcohol, fungicide, and sodium hypochlorite (P1); alcohol and sodium hypochlorite (P2); sodium hypochlorite (P3), and washed on sterile distilled water as control (C). The explants were then cultured on MS solid medium in tubes and jars. Growth and multiplication of shoots were carried out on MS solid medium added with cytokinins (BA and kinetin) at different concentrations. The results showed that the best sterilization method was obtained in the sodium hypochlorite (P3) and alcohol-sodium hypochlorite (P2) treatments, with sterile shoots reaching 100%. Planting the explants in jars gave higher normal shoot formation (85–100%) than that in tubes (12.5–48%). The use of kinetin at 0.5–1 mg L-1 gave good shoot vigor. The best axillary shoot multiplication was found on media with 0.5 mg L-1 BA.  Growing explants on the semi-immersion system and sodium hypochlorite sterilization produced the highest sterile ones, whereas culturing three explants promotes normal growth straight after sterilization.