Direct organogenesis from vegetative explants of Gerbera jamesonii L. cv. Nilo

Developing a highly efficient protocol for plant regeneration is a prerequisite for successful gene transformation in plants. To gain these properties, several experiments were conducted on various explants to optimize the concentration of plant growth regulators in regeneration of Gerbera. In the first experiment, regeneration of Gerbera plant was investigated using different explants including intact leaf, petiole, scratched petiole and Thin Cell Layer (TCL). Moreover, combination of BAP (0, 1, 2 and 3 mg L-1), TDZ (0, 0.1, 0.5, 0.8 and 1 mg L-1) and IAA (0.1 mg L-1) under 16/8 h light/darkness condition or one-month darkness were considered. In the second experiment, the regeneration potential of the first, second and third disc of TCL cut off from the end of the detached petioles were evaluated. Effect of different combination of BAP (0, 1 and 2 mg L-1), TDZ (0 and 0.5 mg L-1) and IAA (0, 0.1 and 0.3 mg L-1) on regeneration was studied. In all experiments, the MS-basal medium was used. The results showed that the best regeneration medium for intact leaf (33.2% regeneration, 66.3 shoots), petiole (86.66% regeneration, 33.33 shoots) and scratched petiole (53.2% regeneration, 33.10 shoots) was MS medium containing 2 mg L-1 BAP under 16/8 h light/darkness condition, and for TCL explants (46% regeneration, 29 shoots), 2 mg L-1 BAP with 0.5 mg L-1 TDZ in the darkness. In the second experiment, the highest rate of regeneration was obtained from the first disc of TCL explants on the MS medium containing 2 mg L-1 BAP, 0.5 mg L-1 TDZ and 0.1 mg L-1 IAA.