Effect of cytokinins and auxins on plantlet regeneration from nodal segments of Stevia rebaudiana Bertoni

An efficient micropropagation protocol using nodal segments of Stevia rebaudiana Bertoni, a zero calorie natural sweetener, was established. The nodal segments were inoculated on Murashige and Skoog's (MS) medium containing varying concentrations of different cytokinins viz. BA (benzyl adenine), KN (kinetin) and 2-iP (N⁶-(2-isopentyladenosine). Maximum shoot induction (79.16%) was achieved on MS medium supplemented with KN (6.0 mg/l) where 2.33±0.21 shoots were generated per explant with an average height of 4.33±0.93 cm after 30 days of culture. For faster multiplication, the shoots were transferred to fresh MS medium containing KN (6mg/l) + BA (4mg/l). Full strength MS medium fortified with indole butyric acid (IBA) and naphthalene acetic acid (NAA) in the range 0.1–1.0 mg/l was employed for rooting. Rooting frequency was maximum (75.42%) with MS + IBA (0.1 mg/l). The micropropagated plantlets were successfully acclimatized with a survival rate of 68%.