CIM: Callus induction medium, CIM0: Hormone-free (control), CIM1-CIM18: Medium contain MS basal salts+B5 (Gamborg’s) vitamins with different phytohormone concentrations mentioned in table, B1: MS basal salts (difference in some inorganic salt concentration in MS: 16.8 mg L-1 MnSO4.7H2O, 10.6 mg L-1 ZnSO4.7H2O, 0.88 mg L-1 KI, 1 mg L-1 Thiamine+1 mg L-1 BAP, pH = 5.95)