<正>我们用常规石蜡切片法,借助光学显微镜观察研究了中国鹅掌楸(Liriodendron chinense (Hemsl.) Sarg)的花芽分化,结果如下:(1)花芽通常于果熟后期开始分化。越冬的离心皮雌蕊原基仅在基部稍有卷合,子房与胚珠同时发育,每个子房具两枚悬垂的倒生胚珠:厚珠心,双珠被,“之”字形珠孔;传粉期间又发育了承珠盘、珠孔塞和珠心冠原等衍生结构。蓼型胚囊,开花时为二核期。(2)雄蕊于造孢期越冬,腺质绒毡层,四分体形成为同时型,排列方式以十字交叉型和四方型为主;有少量缢裂现象,属中间型,向心发育,撤粉时为二细胞花粉。最后讨论了花芽分化中原始性状的意义以及结籽率低的原因。

Flower bud development in Liriodendron chinense (Hemsl . ) Sarg. is studied with the light microscope and by the normal palaffin-embedded method. The observation lies in two aspects: (l) Usually, the flower bud’s differentiation is in the later of mature stage of the fruit. The apocarpy pistil primordium only has a little curl in its base throughout the winter. The ovary and the ovule develop simultaneously. Each ovary has two pedulous anatropous: thick nucellus, double integement and a z-shaped micropyle , and the hypostase, obturator, nucellar cap have also developed in the ovule during the pollination. It’s the Polygonum-type embryo sac and it is always in the two nucleared periods when it blooms. (2) The stamen is in the sporogenous period throughout the winter. The gladular taptum and the formation of tetrad is of the simultaneous type. The mostly tetrad follows the tetrahedron type and the decussate type. Some strangling division phenomenon is also found, and follows the intermediate type. They develop centripetally. Pollens shed as single grains with two-cells. The primitive character of the flower bud’s differentiation and the reason of low seeding rate are also discussed.