Cytological observation of cytoplasmic male-sterile anther of brown cotton.

Cytological observation of microsporogenesis was performed for a cytoplasmic male sterile (CMS) line of brown cotton comparing with its maintainer line. The result showed that abortion of auxocyte cells in CMS anthers took place during the development periods of sporogneous cells and microspore mother cells (MMC's). Abortion characteristics were abnormal behavior of chromosomes, formation of multi micronucleli in one cell, high frequency of nucleolus penetration through nucleus envelop and cell wall, high vacuolization of cytoplasm and coalescence of MMC's. As compared with the tapetal cells of the fertile anther, those of the sterile anther were significantly smaller and vaculolarer. It was suggested that the abnormality of tapetum development was associated with the abortion of MMC's.