Abstract

The aim of present investigation was to develop a highly reproducible and well documented protocol for in vitro germination and multiplication of highly valuable medicinal herb, Picrorhiza kurroa via callus mediated organogenesis using the axenic epicotyls originated from in vitro germinated seedlings. Highest germination percentage (88.6) was observed in stratified seeds (4°C for 5 days) treated with 100 mg/l GA3 and maintained at 25 ±1°C under continuous light conditions. Out of different combinations of plant growth regulators tested, Murashige and Skoog (MS) medium supplemented with 1.5 mg/l α naphthalene acetic acid (NAA)+0.75 mg/l kinetin (Kn)+0.75 mg/l 6-benzyladenine (BAP) was found best for callus induction and further proliferation. Addition of gibberellic acid (GA3) at 1.0 mg/l concentration in hormonal combination of 2.0 mg/l Kn and 0.75 mg/l indole-3-acetic acid (IAA) was found to be optimum to produce highest shooting response (95%) with an average number of 11.40 shoots per calli. The rooting was optimized using 0.5 mg/l IAA with 85% response. The plantlets with well-developed roots were hardened and were successfully acclimatized in field conditions. This protocol may offer the potential to substantially reduce the pressure of commercial need of this valuable herb on wild stock.