Abstract
An efficient plant regeneration protocol was described for castor (Ricinus communis L.) using whole cotyledonary nodes as explant. Seeds were surface sterilized with 0.1% (w/v) mercuric chloride and germinated in growth regulator-free MS medium. Cotyledonary nodes were excised from 5-7 days old seedlings and were cultured on Murashige and Skoog (MS) medium supplemented with different concentrations of BAP, Kin singly or in combination with NAA. Use of BAP at 3.0 mg.l(-1) induced the highest frequency (85%) of shoot induction as well as maximum number of shoots per explant (12.56). Proliferated shoot clusters were elongated in 1.0 mg.l(-1) BAP in combination with 0.25 mg.l(-1) GA(3). For root induction, in vitro shoots were transferred to rooting media containing NAA or IBA. The highest rooting frequency (87.5%) as well as highest number of roots (10.5) was observed in MS medium supplemented with 1.0 mg.l(-1) NAA. Regenerated plantlets were acclimatized successfully in the growth room for further development.