Abstract: Effect of explant, site of leaflet, induction period in the dark and combinations of plant growth regulators on adventitious bud induction and plant regeneration of Rosa hybrida cv. Samantha was investigated. The results showed that after 8 days of induction on MS medium with 1.5mg·L-1 TDZ and 0.05mg·L-1 NAA in the dark and a subculture on MS medium with 0.5mg·L-1 BA and 0.01mg·L-1 NAA under light, the best plant regeneration was obtained and the regeneration frequencies of leaflets and petioles were 51.8% and 10%, respectively. There was no significant difference in regeneration ability between leaflets at different sites of the leaves. Longer time of induction in the dark caused callus formation and the regeneration frequency was significantly reduced. High concentration of auxin resulted in callus growth which was disadvantageous to shoot regeneration.

Key words: Rose (Rosa hybrida ), Adventitious bud, Plant regeneration