2.5. Callus Induction
After sterilization, about 1cm2 leaf disc of the three Jatropha accessions (Metema, Adami Tulu and Shewa Robit accession) were transferred to callus induction media consisting of MS basal medium supplemented with various combinations of 2, 4-D (0, 0.5, 1.0, 1.5 mg/L) and BAP (0, 1.0, 1.5, 2.0 mg/L). Five leaf disc explants per jar were used and each treatment was replicated five times. All the cultures were incubated at 25 ± 2°C in darkness to promote callus formation and discourage greening of the callus. The percentage proportion of callus induction on leaf discs was evaluated at an interval of four weeks after inoculation of explant.