Highest callus induction frequency (50%) was observed in the stem explants pre-treated with silver nanoparticles suspension (AgNPs: 50 ppm) and cultured on MS media supplemented with combination of 6-Benzylaminopurine (BAP: 2 mg/l), Gibberellic acid (GA<sub>3</sub>: 1.5 mg/l) plus Naphthalene acetic acid (NAA: 0.5 mg/l).
The best mucilage production from callus (36.76% g g<sup>-1</sup> dry weight) was obtained in the MS medium supplemented with 1 mg L<sup>-1</sup> of 2, 4-D and 2 mg L<sup>-1</sup> of BAP under the light condition.
For callus induction, an experiment was laid out as a factorial experiment with three factors (explant type, different concentrations of BAP and 2,4-D) based on completely randomized design with three replications.