After 1 week in the callus induction medium, the explants started to swell. For those growing in the MS basal medium without auxin (control), no little callus was induced even after 30 days, indicating that plant-growth regulators are required for callus induction. Single BAP or the combination of BAP (1, 2 and 3 mg/l) and NAA (0.2 mg/l) in medium promoted the differentiation of shoot from the callus, but increase in the concentration of NAA slightly suppressed the differentiation.