山桐子花芽分化及雌雄配子体发育

Flower Bud Differentiation and Development of Male and Female Gametophytes in Idesia polycarpa

利用常规石蜡切片技术对山桐子花芽分化与配子体的发育过程进行研究。结果表明,山桐子花芽分化可划分为6个时期：花芽未分化期、花芽分化初期、花序轴分化期、花序分化期、花器官分化期、雌雄蕊形成期。山桐子的花芽分化始于8月下旬,在形成花序轴原基之后进入休眠期。花药壁由表皮、药室内壁、中层（2-3层）、绒毡层组成。小孢子母细胞经过减数分裂形成四分体,四分体为四面体结构,成熟花粉为2-细胞型。子房1室,多胚珠;胚珠倒生;双珠被,厚珠心;大孢子四分体为直线型,合点端大孢子发育成功能大孢子,胚囊发育为蓼型。

The paraffin section method was used to observe the process of flower bud differentiation and gametophyte development of Idesia polycarpa. The results showed that the floral bud differentiation could be divided into six stages： before floral bud differentiation stage,initial floral bud differentiation stage,rachis differentiation stage, inflorescence differentiation stage, floral organ differentiation stage, and floral organ formative stage. Floral bud differentiation started in August and ended when rachis primordium developed. The consistent of wall of anther were epidermis,endothecium,two or three middle layers and tapetum from surface to inside. Cytokinesis in the microsporocyte meiosis was of the continuous type. Microsporocyte tetrads were tetrahedral. Mature pollen grains were 2-celled. The ovary was one 1ocular. Ovules were anatropous, bitegminous and crassinucellate. The meiosis of megaspore mother cell was normal. The megaspore tetrad was linear,but only the megaspore near the chalazal last remained. The formation of embryo sac was polygonum type.