Cytological Observation of Microsporogenesis in the Male Sterile Line of Verbena hybrida

Paraffin section was employed to observe the morphological features at different microsporogenesis stages of male sterility Verbena B-58 and its maintainer with light microscope.The result showed that in fertile line,development of the mature pollen grains was followed through the initiation of the sporogenous cell,microsporocyte formation and the tetrad development period.In the male sterile line,microspore abortion occurred at the tetrad stage and no mononuclear pollen was observed.Because the degradation of tetrad callose wall was abnormal,microspore disaggregated thoroughly in the collose wall.Tapetum layer cells began to vacuolated and disaggregated lately.