Plant regeneration ability was studied in the medicinal-ornamental Cosmos bipinnatus cv. Sonata white which is a dicotyledonous recalcitrant plant to shoot induction. Leaf, stem and cotyledons were used . Leaf, stem and cotyledons were used as explantexplants source to investigate. Also ability of explants for direct and indirect plant regeneration was tested. No indirect shoot induction was observed and the direct shoot induction was only occurred on cotyledonary explants. High frequency of direct shoot induction was obtained when BA (5mg/l) and AgNO3 (5 mg/l) were used in combination with 20 mg/l adenine sulphate (73.75%) in MS medium. The highest shoot number per explant was induced on MS medium supplemented with 5 mg/l BA, 5mg/l AgNO3 and 40 mg/l Adenine (5.67). Six weeks old plantlets were transferred to MS medium containing 1 mg/l BA for further proliferation and growth. Upon to plantlets transferring to MS hormone-free medium, flowers were appeared. In Ffour weeks later, root formation was occurred on half MS medium with 1mg/l IBA.
