Indirect Regeneration of Withania somnifera from Nodal Explants

Withania somnifera is an important medicinal plant and used to cure many diseases. Indirect regeneration protocol for multiple shoots development was established using nodal explants of W. somnifera from 50-60 days old seedlings. The callus induction was observed from nodal explants, grown on Murashige and Skoog (MS) medium supplemented with various concentrations and combinations of 2,4-dichlorophenoxy acetic acid (2,4-D) and kinetin (Kn). Maximum level of callusing response (80.0%) was recorded on MS medium supplemented with a combinations of 2.0 mg/l 2,4-D and 0.2 mg/l Kn. The callus (greenish compact) was transferred into MS medium containing various concentrations (0.5–2.0mg/l) of 6-benzyl amino purine (BAP) alone and in combination (0.1–0.4mg/l) with indole-3-acetic acid (IAA) for shoot initiation and proliferation. The maximum number of shoots was initiated from callus on 1.0mg/l BAP along with 0.2 mg/l IAA and proliferation of shoots achieved by subsequent subcultures at 4 weeks interval in the same medium. The maximum of 31.4 shoots/explant were achieved in the second subculture. MS medium along with 1.0 mg/l gibberellic acid (GA3) induced maximum elongation (96.7%) of regenerated shoots and MS medium supplemented with 0.8 mg/l indole-3-butyric acid (IBA) induced maximum rooting (96.7%) from elongated shoots. After a hardening period, the plantlets were transferred to the field with 98% of survival.