Momordica cochinchinensis (Dumbaya) is a local plant with high nutritional and medicinal potential, but its propagation is constrained by hard seed coats and low natural regeneration capacity. Tissue culture via callus induction offers an alternative strategy to support efficient propagation and further in vitro studies. This study aimed to develop a hypocotyl-derived callus induction protocol for M. cochinchinensis using different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) and 6-benzylaminopurine (6-BA). The scientific contribution of this study lies in establishing a preliminary callus induction protocol using hypocotyl explants of Dumbaya, a local germplasm that has received limited attention in in vitro culture studies. Hypocotyl segments from four-week-old in vitro seedlings were cultured for eight weeks on Murashige and Skoog medium supplemented with three plant growth regulator combinations: A1, 2.0 mg L-1 2,4-D + 0.5 mg L-1 6-BA; A2, 1.5 mg L-1 2,4-D + 0.75 mg L-1 6-BA; and A3, 1.0 mg L-1 2,4-D + 1.5 mg L-1 6-BA. All tested treatments induced friable callus. Treatment A3 showed a trend toward higher fresh weight and more favorable yellowish white callus morphology, although the differences among treatments were not statistically significant. These findings indicate that 1.0 mg L-1 2,4-D combined with 1.5 mg L-1 6-BA may serve as a preliminary starting formulation for producing hypocotyl-derived callus of M.cochinchinensis for further regeneration, conservation, and secondary metabolite-related studies.
