镉对洋葱根生长和细胞分裂的影响

研究了不同浓度氯化镉溶液对洋葱根的生长,细胞分裂和染色体形态的影响.结果表明,随Cd~(2+)浓度增加,根的生长速率递减;随处理时间延长,每单位时间的根生长速度递减或停止,根尖细胞有丝分裂指数随Cd~(2+)的浓度增高和处理时间延长而递减.不同浓度Cd~(2+)都能引起染色体畸变,恢复培养后均能恢复生长,染色体畸变率降低

EFFECTS OF Cd2+ ON ROOT GROWTH AND CELL DIVISION OF ALLIUM CEPA

The effects of cadmium chloride solution of different concentrations on root growth, cell division and chromosomal morphology of Allium cepa were studied. The results showed the rate of root growth decreased successively with increasing Cd2+ concentration; the speed of the root growth per time unit also decreased successively or stopped with increasing treatment duration; the mitotic index decreased progressively with increasing Cd2+ concentration and treatment duration; the different concentrations of Cd2+ treatments could induce chromosomal aberration, after recovery culture the bulbs of onion in all treatments could grow and the chromosomal aberration decreased. The possible mechanism on poisoning of Cd2+ to root meristem cells of Allium cepa was also briefly discussed.