中国鹅掌楸花芽分化的细胞形态学观察

THE OBSERVATION OF CELL PHYTOMORPHOLOGY OF THE BUD'S DIFFERENTIATION IN THE LIRIODENDRON CHINENSE (HEMSL.) SARG.

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.