Histological Observation of Microsporogenesis in Cytoplasm Male Sterile(CMS) Line of Radish(Raphanus sativus L.)

The paraffin method was used for histological observation of microsporogenesis of the male sterile line RS-CMS2.The male sterile line began to abort when microspores at tetrad stage.The tapetal cells enlarged abnormally at meiotic phase and presented many large vacuoles.Then with the degeneration of the tapetal cells,microspores conglutinated each other and fused to form a big conglomeration.Finally,the pollen grains aborted completely.This result would be helpful to understand the mechanism of cytoplasm male sterile(CMS) and to increase the breeding efficiency in the future.