In vitro regeneration protocol through direct organogenesis for Jatropha curcas L. (Euphorbiaceae) accessions in Ethiopia

Jatropha curcas L. is among important tree crops in the world with a potential for biofuel production. In Ethiopia, there is a soaring investors’ interest to produce Jatropha in the country for biodiesel production. However, insufficient good quality propagation material is a major production constraint. A study was undertaken to establish a protocol for in vitro mass propagation of three Ethiopian Jatropha accessions viz. Metema, Adami Tulu and Shewa Robit through direct organogenesis from nodal explant. The result revealed that the highest percentage of shoot induction (86-90%) was achieved on MS medium with BAP (1 mg/L) and IBA (0.5 mg/L) for all the three accessions. The maximum number of shoots (6) was obtained for Metema when BAP (0.5 mg/L) with Kn (0.5 mg/L) was used. Whereas, the maximum (3.2 cm) shoot length was recorded for Shewa Robit on media with 0.5 mg/L Kn. The highest rooting percentage (84.8-88%) and maximum root number (5.43) were recorded on media supplemented with 0.25 mg/L IBA. Shewa Robit and Metema had longer roots on media with 0.25 mg/L IBA. Finally, the plantlets were successfully established in greenhouse with survival rate of 86.67% for Shewa Robit followed by 73.33 and 66.67% for Metema and Adami Tulu, respectively. This study provided optimal protocol for micro-propagation of Jatropha accessions through direct organogenesis to boost its production.     Key words: Jatropha curcas, biofuel, organogenesis, plant growth regulators.