The embryological study of Tugarinovia mongolica I.Megasporogenesis、microsporogenesis and development of gametophytes

Tugarinovia mongolica is dioecious plant.In male flowers,the anther has four chambers.The development of anther wall is dicotyledonous type which is composed of epidermis,endothecium,one layer of middle layer and amoeboid tapetum.The tapetum begins to vary at the stage of tetrad with the cytoplasm moving into the anther cell.The cytokinesis of microspore mother cell in meiosis is simuteneous,and the tetrad are tetrahedral.The mature pollen grain is 3 celled.The big,empty and abortive pollen grains are abserred at the stage of uninuclear microspore.In female flowers,Ovule is anatropous,unitegmic and tenuinuceuate with the development of integument finished at the stage of archespore.The megaspore mother cells are developed directly by a hypodermal archesporical cell.Which undergoes meitotic division and forms a linear tetrad.The embryo sac is of Polygonum type.Some abnormal mature embryo sacs are observed.The problem of the relations between the environment and the development is discussed on the foundation of the study of the histochemical changes.