Megasporogenesis, Microsporogenesis and Development of Female and Male Gametophyte of Bupleurum chinense

Paraffin wax specimens of Bupleurum chinense DC. were used to observe the whole process of embryo development, including megasporgenesis, microsporgenesis, and the development of female and male gametophytes. The anther is tetrasporangiate and its wall conforms to the Dicotyledonous type developmentally. The anther wall includes 4 layers: epiderm, endothecium, middle layer and tapetum. Simultaneous cytokinesis in the microspore mother cells follows meiosis, and the microspore tetrads are tetrahedral. Pollen grains are 3 celled when shed. The ovule is anatropous, unitegmic and tenuinucellar. Usually one archesporium functions directly as a megaspore mother cell. Cytokinesis in the megaspore mother cell usually accompanies meiosis, and the chalazal megaspore of a linear or T-shape tetrad develops into a Polygonum-type embryo sac. The innermost layer of the integument differentiates as an endothelium tapetum. In the same bud, the stamen develops earlier than the pistil. We compared the bud size and development stage of pistils and stamens.