Abstract
In the present study the effect of inorganic nutrients (CuSO4 & ZnSO4) on morphogenic and biochemical responses from nodal explants in Withania somnifera L. was investigated. Incorporation of either Copper sulphate (25-200 mu M) or Zinc sulphate (50-500 mu M) in the optimized Murashige and Skoog (MS) medium highly influenced the shoot bud formation and subsequent elongation, which induced maximum percentage (95%) regeneration, number (61.7 +/- 0.25) of shoots with shoot length (5.46 +/- 0.16 cm) on CuSO4 (100 mu M) and maximum percentage regeneration (100%), number of shoots (66.1 +/- 0.96) with shoot length (6.24 +/- 0.21 cm) on ZnSO4 (300 mu M) after 12 weeks of culture. Healthy growing in vitro microshoots rooted efficiently on 1/2 MS medium supplemented with NAA (0.5 mu M), which induced (16.2 +/- 0.12) roots with root length (3.30 +/- 0.12 cm) after 4 weeks. Pigment content increased with increasing concentration of Cu and Zn and the maximum Chl. a (0.47), (0.41); Chl. b (0.52), (0.42); total Chl. (0.99), (0.83) and Carotenoid (0.16), (0.16) mg/g FIN contents in regenerants were found on CuSO4 (100 mu M) and ZnSO4 (300 mu M), respectively. Maximum proline content (0.17), (0.16) mu g/g FW was observed on high concentrations of CuSO4 (200 mu M) and ZnSO4 (500 mu M) respectively, in the basal medium. Regenerated plantlets were acclimatized successfully in soilrite with a survival rate of 95%. No morphological variations were detected among the micropropagated plants when compared with seedling raised plants of the same age. (C) 2011 Elsevier Masson SAS. All rights reserved.