Morphogenic responses of Rauvolfia tetraphylla L. cultures to Cu, Zn and Cd ions

Abstract

The present work was undertaken to study the effect of heavy metals on morphogenic response from nodal explants of Rauvolfia tetraphylla L. The approach has been found to be significant for enhanced multiple shoot induction on Murashige and Skoog (MS) medium containing various concentrations of copper (Cu), zinc (Zn) and cadmium (Cd). Among various concentrations used, the optimum regeneration was recorded on MS medium supplemented with 10 µM 6-benzyladenine, 0.5 µM α-naphthalene acetic acid, and 100 µM zinc sulphate which exhibited 12.2 shoots per explant with 2.5 cm shoot length after 12 weeks of culture. In case of copper sulphate, the optimum concentration was found to be 20 µM with 11.6 shoots per explant and 3.3 cm shoot length. Cadmium chloride was found to be most toxic as it showed negative effect on shoot regeneration. Healthy growing in vitro microshoots (3 cm) rooted efficiently on ½ MS medium supplemented with indole-3-butyric acid (0.5 µM) which induced 4.8 roots with 1.8 cm root length after 4 weeks. Regenerated plantlets were successfully hardened off in Soilrite followed by their transfer to garden soil under normal sunlight.