High frequency plant regeneration in Ashwagandha [Withania somnifera (L.) Dunal].: An important medicinal plant

Abstract

A high frequency and rapid regeneration protocol via callus and directly from various explants was developed in Withania somnifera (L.) Dunal. Callus was initiated from internodal segment, leaf, root and petiole explants on MS and B5 media supplemented with 2,4-D (0.5-3.0 mg/l) and NAA (0.5-3.0 mg/l) either alone or along with Kinetin (0.5-1.0 mg/l). Regeneration was observed from callus of all the explants except roots on MS medium fortified with BAP (0.5-2.5 mg/l) or in combination with IAA (0.5 mg/l). Direct differentiation of multiple shoots from leaf, nodal segments and shoot tips occurred within two weeks on MS medium supplemented with BAP (0.5-3.0 mg/l) in combination with IAA (0.5 mg/l). The number and height of the shoots per explant varied with different concentrations of BAP with low concentrations of IAA. Shoots that were dwarf were elongated on MS medium fortified with GA 3 (0.5 mg/l). These plantlets were then rooted successfully in half strength MS media (both liquid and solid) with IBA (0.5-1.0 mg/l) alone or along with IAA (0.5 mg/l). Plantlets were hardened for two weeks and successfully transferred to field with 80-85% survival.