Studies On Cytoplasmic Male Sterility Of Cabbage

For clarifying the mechanism of cytoplasmic male sterility in cabbage, the cytoplasmic male sterile line 99A and its maintainers 99B of cabbage were studied through observation of morphology and cytology, analysis of the physiological and biochemical characteristics. The main results were showed as follows.1.Compared with the male container line 99B, the flower of male sterility line has smeller petals and opening angle, shorter filament and thinner anther. But the nectary and pistil of male sterility line are normal. Sterility plant rate and sterility rate of the offspring produced by male sterility line pollinated by its maintainer line remain 100%.2.The meiosis of microspore mother cells of male sterility line is normal. Most of microspore mother cells could develop into the tetrad stage and a few could develop to the single nucleus microspore stage. But the tapetum cells in the male sterile line began to overgrow with vacuole during early meiotic prophase and the overgrowth reached the peak before or after microspore formation, and at the same time the microspores were adhered and centralized, finally the anther became shrinking and the microspores disaggregate completely.3.With flower bud developing, the bands number of EST and COD isoenzyme in flower buds in cytoplasmic male sterile line compared with those of its maintain line in cabbage were not only increased, but also the activity increased. POD isoenzyme activity was higher than the maintain lines too. Two of ATP isoenzyme bands were missing in male sterile flower buds. The activity of COD isoenzyme in the leaves of cytoplasmic male sterile line was lower compared with those of its maintain line, EST isoenzyme was of higher activity and increased one bands, and POD isoenzyme missed one band.4.With flower bud developing, the superoxide anion radical formation rate, and content of malonadehyde and hydrogen peroxide in flower buds of cytoplasmic male sterile line were higher than those of the maintainer line. The activitie of peroxidase (POD) and superoxide enzyme (SOD) were higher, but catalase (CAT) activity was a little lower.