花叶千年木花序梗愈伤组织直接再生花芽的初步研究

A Preliminary Study on Direct Regeneration of Flower Buds from Peduncle Calli in Dracaena fragrans cv. massangeana

在离体条件下，诱导愈伤组织或外植体直接再生花芽已经在许多草本植物上取得成功［１～７］，而就木本植物来说，迄今尚未见到成功的报导。诱导愈伤组织或外植体直接再生花芽所形成的离体培养实验系统将十分有利于研究雌、雄性器官分化和发育所必需的条件［８］和找到所需...

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 GA 3 into the medium on which the calli had differentiated into flower buds, the flower buds would gradually wither after 2 weeks in culture.