Effect of nitrogen and carbon sources on in vitro shoot multiplication, root induction and withanolides content in Withania somnifera (L.) Dunal

Effect of nitrogen and carbon sources on multiple shoot regeneration and withanolides contents of Withania somnifera were evaluated. Inclusion of L-glutamine (20 mg/l) in medium fortified with the optimal levels of 1.5 mg/l 6-benzyladenine (BA) and 0.3 mg/l indole-3-acetic acid (IAA) resulted in the production of 58 shoots/explant. Sucrose at 4 % and 20 mg/l L-glutamine with ide ´al concentrations of BA and IAA improved shoot multiplication (62 shoots/explant) while 6 % sucrose enhanced withanolides contents in regenerated multiple shoots. All the shoots were rooted (26 roots/shoot) when cultured in MS medium amended with 15 mg/l ammonium nitrate, 2 mg/l IBA, and 2 % sucrose. The present study resulted in the production of 4.42-fold higher multiple shoots and 2.6- fold higher roots as well as enhancing the contents of all major withanolides (withaferin A, withanone, withanolide A and B) in regenerated plants when compared to previous reports on W. somnifera regeneration.