transferred to half-strength and full-strength MS basal medium supplemented with different concentrations of activated charcoal (100 mg L-1 and 200 mg L-1), indol acetic acid (IAA, 0.5 mg L-1 and 1.0 mg L-1) and naphthalene acetic acid (NAA, 0.5 mg L-1 and 1.0 mg L-1).