Abstract: Flower buds were directly regenerated from calli in vitro in the woody plant Dracaena fragrans cv. massangeana Hort. On modified MS medium supplemented with 1.0 mg/L 6-BA and 1.0 mg/L IBA, two kinds of calli, A and B, were formed from the peduncle explants cultured for 5 months. Calli A were loose and on their surface there were many irregular granule-like structures (GLC); Calli B were compact and had bigger tumor-like structures (TLC) on their surface. When the GLC and TLC were transferred onto the medium respectively with 0.4 mg/L 6-BA and 1.0 mg/L IBA, flower buds were differentiated directly from the GLC but only vegetative buds and roots were differentiated from the TLC after culturing for 4 weeks. The GLC could be partly transformed into TLC in the continuous passage culture. Assays on hormones revealed that at a fixed IBA concentration of 0.4 mg/L the defferentiation frequency of flower budding was increased as the 6-BA concentration was decreased from 2.0 mg/L to 10 mg/L. Alternatively, at a fixed 6-BA concentration of 2.0 mg/L, the flower budding frequency was increased when the IBA concentration was changed from 0.4 mg/L to 1.0 mg/L. Moreover, the addition of 2.0 mg/L zeatin to the culture medium containing 2.0 mg/L 6-BA and 0.4 mg/L IBA was favorable to the regeneration of the flower buds. Nevertheless supplementing 1.0 mg/L GA3 into the medium on which the calli had differentiated into flower buds, the flower buds would gradually wither after 2 weeks in culture.

Key words: Dracaena fragrans cv. massangeana, Regeneration of flower buds, Tissue culture