Callus cultures were transferred to CPM containing 800 mg/l cefotaxime (Table 1) for two weeks. Surviving calli were further subcultured onto shoot induction medium (SIM) containing 600 mg/l cefotaxime for two weeks. In a third subculture, cefotaxime was decreased to 400 mg/l. The surviving calli were transferred to shoot profileration medium (SPM, Table 1) for one month.