Efficient Micropropagation Protocols of Regeneration of Stevia rebaudiana Bertoni, An anti-diabetic Herb

Micropropagation protocols of Stevia rebaudiana Bertoni, an important medicinal plant of Asteraceae family have been developed using nodal segments in half strength MS media. Stevia is an anti-diabetic plant used as sweetening agent in industrial sector and is commercially important. Stevioside, the bio-active compound in its leaves, tastes about 300 times sweeter than sucrose. Its other medicinal uses include regulating blood sugar, preventing hypertension and tooth decay as well as treatment of skin disorders. Due to poor seed viability and low germination rate, the common method of propagation is restricted. Keeping in view its utmost medicinal values in account, in vitro culture study was attempted to raise the stevia plants through effective protocol. Shoot multiplication enhanced significantly in half strength MS medium at various hormonal concentrations of Benzyl amino purine (BAP), Kinetin (Kn), Indole acetic acid (IAA), Indole butyric acid (IBA), both alone and in combination. Lower concentrations of growth regulators, in general, are more effective. Single use of Kn (0.5 mg/l) as compared to BAP produced best shooting response, whereas, when various combinations of cytokinins and auxins were considered BAP and IBA (0.2 mg/l each) produced maximum shoots (2.75) with moderate shoot length (1.70 cm) and good number of leaves (28). In vitro rooting of microshoots was effective in MS medium supplemented with IBA (1.0 mg/l) and activated charcoal (50 mg/l). The survival of the hardened in vitro raised plants, under controlled condition was 90%. The field transplantation of these plants showed 70% survival after 2 months.