[Effect of gibberellin on direct regeneration of floral buds from young flower buds in Sinningia speciosa Hiern].

The phenomena of direct regeneration of floral buds on young flower bud and sepal cultures in vitro were observed in Sinningia speciosa Hiern. The gibberellin concentration in medium was very important for inducing the direct regeneration of floral buds. No direct floral bud was regenerated when the concentration of gibberellin (GA) supplemented in medium was equal to or less than 0.5 mg/L. The young floral buds and sepals inoculated on modified Murashige and Skoog (MS) medium supplemented with 1.0-1.5 mg/L GA and 0.1 mg/L 6-benzylaminopurine (BA) for 40 days produced floral buds directly on the surface of the sepals. There were two types of the floral buds regenerated directly: one was only with floral buds, which was up to 14.3%; the other was with both floral and vegetative buds, which was up to 28.6%. The effect of exogenous GA on the formation of floral buds in Sinningia cultured in vitro is discussed.