Cell Dedifferentiation in Stevia Rebauiana as a Pharmaceutical and Medicinal Plant

Stevia is a natural and non-caloric sweetener which most used in food and drug industries. In the present study, we focused on optimization of cell dedifferentiation and callus induction in stevia. In order to evaluation of growth regulators and explant types effects on callus induction, a factorial experiment was carried out in two factors and based on completely randomized design in four replications. The factor A included different levels of benzene adenin in three levels (0.0, 0.5 and 1.0 mg/l), Naphthalene acetic acid in four levels (0.0, 0.5, 1 and 2 mg/l), 2-4-D in three levels (0, 1 and 2 mg/l). The factor B comprised two levels of explant (leaf and stem) that were evaluated. The experiment was performed on Tissue Culture Lab in Kermanshah Industrial University. Analysis of variance for data results showed that there were significant differences among levels of plant explants for callus induction (P<0.05). However differences among above levels were not significant for callus growth rate. There were significant differences among plant growth regulators levels for callus induction and callus growth rate (P<0.01). Interaction effects were not significant for above two traits. Means comparison for plant growth regulators via Duncan's test (p<0.5) showed that medium plants supplemented with N0.5B0.5 was the best medium for callus induction (97.5%). The medium included N1B1 showed the highest callus growth rate (0.1 mm/day). In conclusion, we described a role of plant growth regulators and explant types on callus induction in stevia.