[Morphological studies on direct regeneration of floral buds from in vitro cultures of sepal segments in Sinningia speciosa hiern].

The morphological changes in the cultures of sepal segments in Sinningia speciosa Hiern were observed with Zeiss Stemi 2000-C Stereomicroscope from 0 to 65 days after culture in vitro. The light yellow globular protuberances were observed on the cut edge and the surface of sepal segments after culture for 24 days. Then the globular protuberances grew bigger gradually.

[Expression of CFL gene during differentiation of floral and vegetative buds in cucumber cotyledonary nodes cultured in vitro].

CFL gene, a LFY homologue, was cloned from cucumber (Cucumis sativus L.). In this paper, in situ hybridization was performed to analyze the expression pattern of CFL gene at the stage of floral and vegetative buds differentiation in cucumber cotyledonary nodes cultured in vitro.

[Regulation network and biological roles of LEAFY in Arabidopsis thaliana in floral development].

Recent research progress on regulation network and biological roles of LFY gene in Arabidopsis thaliana and its homologue genes in floral development are reviewed emphatically in the present paper. LFY gene expresses widely in both vegetative and reproductive tissues in different higher plants, therefore investigation on role of LFY gene on flowering is of general significance. LFY gene plays an important role to promote flower formation by interaction and coordination with other genes,such as TFL, EMF, AP1, AP2, CAL, FWA, FT, AP3, PI, AG, UFO, CO, LD, GA1 etc, and a critical level of LFY expression is essential.

[Studies on calcium sensitive period during floral differentiation of cucumber cotyledonary node cultures in vitro].

Cotyledonary nodes of cucumber cultured on calcium-free medium for 0, 1, 2, 3, 4, 5, 6d respectively, were transferred to medium with 6.0 mmol/L CaCl2 for 24h, then returned to calcium-free medium. Cotyledonary nodes cultured on calcium-free or 6.

[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.

[Relationship between floral differentiation and endogenous hormones and polyamines contents in cucumber cotyledonary nodes cultured in vitro].

Changes of endogenous hormones and polyamines(PAs) contents during floral differentiation (0-6 day) in cucumber cotyledonary nodes cultured in vitro were determined by using HPLC. The results showed that all four endogenous hormones decreased obviously within 0-2 day and increased slightly within 4-5 day after culture. This indicated that low levels of indole-3-acetic acid (IAA), gibberelline(GA3) and abscisin acid(ABA) during 0-2 day were favorable to floral primordia differentiation, while high level of zeatin(ZT) during 3-5 day was favorable to floral organ primordia differentiation.

[Floral homeotic variants of in vitro seedlings in Sinningia speciosa Hiern].

Six types of floral homeotic variants of in vitro seedlings were observed in doubleflower sinningia. Type I, red and green mosaic petals exist in the outermost whorl of petal-whorls, 2.38%.