Micropropagation of purple yam (Dioscorea alata L.) from nodal and petiole explants using different types of plant growth regulators

Yam is one of the tuber root-types that contain multifunctions and nutrients. Previous research quoted that purple yam has been commercially used as food colorant, but there is not much to extract that purple colour since we are lack of the purple yam production. Hence, tissue culture technology was manipulated to produce more purple yam in shortest time through multiple induction of shoots and roots. This was expected to be as the alternative source in gaining natural food colorant. Nodal and petiole were used as the source of explants to establish plant cell culture. Those explants were cultured on medium contained single cytokinin (BAP, TDZ, Kinetin) and combination of both Plant Growth Regulators (PGR) auxin and cytokinin (NAA+ BAP, NAA+ Kinetin, NAA+ TDZ, Kinetin+ IAA, NAA+IP, IAA+ IP). In this study, sterilization of purple yam explants using combination of Tween 20, 95% of ethanol and 10% chlorox were the most suitable surfactants. Moreover, the use of Thidiazuron (TDZ) and BAP hormones were functioned in inducing shoots meanwhile auxin hormone such as NAA actively promote roots rather than shoots. According to this research, the most suitable combination of auxin and cytokinin for inducing multiple shoots were MS + 0.5 mg/l KIN + 1.5 mg/l IAA meanwhile for in vitro rooting, the most suitable medium for cultured was on medium MS + 1.0 mg/l NAA + 0.5 mg/l TDZ. Therefore, these results proved that larger
production of purple yam plantlet can be achieved by tissue culture technology.