Studies on Microsporogenesis and Male Gametophyte Development of Flaveria bidentis(L.) Kuntze

Microsporogenesis and male gametophyte development of Flaveria bidentis(L.) Kuntze were observed by using method of traditional paraffin sections.The results showed that anther was tetrasporangiate,and the development of anther wall was the Basic type,which included an epidermis,an endothelium,a middle layer and a tapetum.The tapetum belonged to amoeboid type and its cells were binucleate.From appearance of archesporial cells to 2-celled pollen stage,the development of tetrasporangiate was asynchronous.The archesporial cells differentiated from single archesporium,the meiosis of microspore mother cells were continuous type and tetrads were tetrahedral.Mature pollen grains were 2-celled with 3 aperture,and obvious spines on thick extine.Huge pollens were observed occasionally.At the MMC stage,the tapetum membrane was formed from the middle layer neighboring tapetal cells,which surrounded tapetum and MMC.