Fertility and Cytomorphology of Anthers in New Cytoplasmic Male-Sterile Lines of Chinese Cabbage (Brassica campestris L. ssp.pekinensis)

In order to determine the stage and pattern of anther abortion, anatomical observations of anthers in cytoplasmic male sterile line 6w-9605A and its maintainer line 6w-9605B in Chinese cabbage (Brassica campestris L.ssp.pekinensis) were made using paraffin sections.Simultaneously,the floral organ and fertility of 6w-9605A were observed.The results showed that the anthers of maintainer line 6w-9605B were normal and the abortion of male sterile line occurred mainly at the differentiation stage of archesporial cells,which accounted for 66.7% of anther abortion and resulted in no pollen sac differentiation.In the remaining 33.3% of abortion anthers,pollen sacs were produced but the development of microspores stopped at the late uninucleate or dinucleate stages,and the hypertrophic tapetal cells compressed the microspores and caused the sterility of pollen grains.The sterility of 6w-9605A was stable and complete (100%).