In Vitro Initiation of Dioscorea alata cv. Ubi Badak for Sustainable Germplasm Utilization

Abstract

Efficient in vitro propagation of Dioscorea alata requires optimization of both surface sterilization and culture conditions to ensure high explant survival and shoot induction. This study evaluated the effects of different sodium hypochlorite concentrations on explant survival, contamination, and phenolic exudation, followed by assessment of activated charcoal and cytokinin (BAP) on shoot induction. Nodal explants were subjected to sterilization treatments using 70% ethanol combined with 10–40% sodium hypochlorite. Culture responses were assessed based on survival percentage, contamination incidence, and phenolic exudation, while shoot induction was evaluated using plant height, number of shoots, and shoot length. The results demonstrated that 20% sodium hypochlorite achieved the highest explant survival (90%) with minimal contamination and phenolic exudation. Higher concentrations (30–40%) induced severe tissue damage, oxidative browning, and reduced survival. For shoot induction, the combination of 2.5 mg/L BAP and 2 g/L activated charcoal significantly enhanced growth performance, producing the highest plant height, shoot number, and shoot length. These findings indicate that successful in vitro establishment of Dioscorea alata depends on a balance between sterilization efficiency and physiological stability, followed by optimized culture conditions. The protocol developed provides a reliable approach for large-scale propagation and germplasm conservation.

Keywords: Dioscoreaceae, Micropropagation, optimization, phenolic, charcoal