Abstract: Optical studies were made on mega- and microsporogenesis,the development of female and male gametophyte and starch dynamics in Panicum maximum through conventional paraffin section.The anther wall consists of epidermis,endothecium,middle layer and tapetum.The globular contents in different size,which have PAS and hematoxylin negative reaction respectively,exist in the epidermal cells during the development of the anther.The outer wall of epidermal cells with spininess becomes slightly thick at mature pollen stage.The meiotic cytokinesis of microspore mother cells conforms to the successive types.The mature pollen is rich in big starch grains.The four linear megaspores are formed by the meiotic division of the megaspore mother cell and the one at the chalazal end develops into uni-nucleate embryo sac.The four-nucleate embryo sac develops into eight-nucleate embryo sac,which is composed of four free nuclei and four cells formed through asynchronous division and cellularization.The mature embryo sac is in accordance with polygonum type.The nucellar cells of the chalazal area have little starch during development of embryo sac.In the embryo sac,the content of starch is greater at the micropylar end than at the chalazal end.Therefore,we suggest that carbohydrates are transported mainly through the nucellar cells of the micropylar area and the surface of embryo sac.

Key words: Panicum maximum, Megasporogenesis, Microsporogenesis, Female gametophyte, Male gametophyte, Starch dynamics

CLC Number: 

• S516.01