Microsporogenesis and Male Gametogenesis in Aesculus chinensis Bunge

The microsporogenesis and development of male gametophyte of Aesculus chinensis Bunge were observed by the method of paraffin sections.The main results as follows:The anther is 4 sporangiates and the development of anther wall is the basic type,which is composed of epidermis,endothecium,middle layer and tapetum.The epidermise consist of one layer of cells and still existed as the anther matured.The endothecium developed banding-shaped thickenings when the anther matured.The young anther wall has 3～4 layer middle layers and degenerated when maturity of the anther.The tapetum has dual origin and belong to secretory type,which degenerated just leavening the tapetal membrane at the time of anther matured.The archesporium derived from the cell under the epidermis.The cytokinesis of the microspore mother cells in meiosis is simultaneous.Most of the microspore tetrads are tetrahedral and lest of them are isobilateral.The walls of the microspore mother cells become thicker by the deposition of callose at the time of meiosis and the callose wall were degenerated at the time of microspores.Mature pollen grain is the 2-celled type with three germinal furrows.