Abstract

The present study describes the development of efficient micropropagation protocol for a commercially important medicinal plant Withania coagulans. Nodal segments were immersed in various concentrations of cefotaxime, viz 100, 250, 500 and 750 mgl^-1 for 5 min and implanted on Murashige and Skoog medium (MS) medium fortified with 6-benzyladenine (BA) (2 to 4 mgl^-1) or indolebutyric acid (IBA) (0.25 to 0.5 mgl^-1) either alone or in combination with different concentrations. Of the four concentrations of cefotaxime tested, the 250 mgL^-1 showed nonphytotoxic effect on cultures and completely eliminated bacterial infection. Direct multiple shoots differentiation occurred in cultured explants without intervening callus phase and the maximum number of shoots (7.2 ± 1.0 per explant) and elongation (7 ± 1.4 cm) were achieved on MS media containing 2 mgl^-1 BA + 0.5 mgl^-1 IBA. For induction of stout root system, the shoot buds were cultured on ½MS medium fortified with different concentrations of IBA (1 to 4 mgl^-1), indole-3-acetic acid (IAA) (0.25 to 1.0 mgl^-1) and kinetin (Kin) (1 to 2 mgl^-1). MS medium with 2 mgl^-1 IBA was found most effective for the induction of stout root system. Well-rooted plantlets were transferred to outside pots containing sterile soil, and sand mixture (2:1) showed 75% survival.

Key words: In vitro, medicinal plant, propagation, Withania coagulans.

Abbreviation

BA, 6-Benzyladenine; IBA, indolebutyric acid; IAA, indoleacetic acid; Kin, kinetin; PGRs, plant growth regulators.