Somatic embryogenesis and plant regeneration from leaf and root explants and from seeds of Eragrostis tef (Gramineae)

In vitro somatic embryogenesis and plant regeneration from root and leaf explants and from seeds were studied using eight genotypes of Eragrostis tef at various concentrations (1-10 mg/l) of 3,6-dichloromethoxybenzoic acid (3,6-D) and 2,4-dichloromethoxybenzoic acid (2,4-D). Optimal conditions for callus growth, embryogenesis and plant regeneration were evaluated. The callus biomass and the ability to regenerate plants were found to be functions of type of explant and hormone concentration. The callus fresh weight from leaf was higher than that from root, and different genotypes differed in their callus fresh weight. Unlike leaf induced callus, the root induced callus showed no significant differences between genotypes and treatments. The fresh weight of callus from seeds of most genotypes studied was similar. The number of direct regenerants from callus maintained on callus induction medium varied among the genotypes studied. On the whole, the number of regenerants from leaf callus was higher than that from root callus at all tested hormone concentrations. 1 and 2.5 mg/l of 3,6-D gave the highest numbers of regenerants from calli transferred to embryogenesis medium. The various tef genotypes differed in their capacity to regenerate plants. Establishment of cell suspension cultures from root and leaf explants was also accomplished.