CALLUS INDUCTION AND IN-VITRO REGENERATION OF TEF [ERAGROSTIS TEF (ZUCC.) TROTTER] FROM LEAF

Tef is the foremost staple cereal grain of Ethiopia. It belongs to the family Poaceae, subfamily Eragrostideae, tribe Eragrostiae and genus Eragrostis. The development and refinement of an in vitro culture syst em for tef is a necessary requirement for utilisation of tef in biotec hnology such as genetic engineering. For a long period of time, Poacea e have been characterised as a rather recalcitrant species for in vitr o culture and genetic manipulation, and only recently has progress bee n made with the major cereal crops. Unlike other cereals and millets, the response of tef to these emerging plant biotechnologies has not be en studied; as a result this study was initiated for the first time.Im mature leaf bases explanted from 1-week-old seedlings of tef plants gr own in vitro from four tef genotypes, i.e. Ada, Deschanger, Gommadie a nd Zuccariaginia, were plated on Murashige and Skoog media with 0, 1, 2.5, 5, 10 mg/L dicamba, 2% sucrose and 0.8% agar, and incubated in th e dark at a temperature of 27 degrees C. High frequency direct somatic embryogenesis is obtained in the dicamba concentration range of 1-5 m g/L and no direct regenerants were obtained at 10 mg/L in all of the g enotypes used. Data for gradient response (embryogenic callus/direct e mbryo formation) of cultured leaf showed that callus induction decreas ed with increasing distance from the leaf base. However, in a few expl ants, callus induction was obtained in the leaf tip of immature leaf. All genotypes used responded similarly. Plants from four genotypes wer e grown to flowering, seed setting and maturity. This first research i n tef tissue culture opens a way for the use of tef in plant biotechno logy, i.e. application of tissue culture and genetic engineering based technologies.