镍对蚕豆和冬小麦细胞毒害程度的超微结构观察

Ultrastructural Observation of Cytotoxicity of Broad Beau and Winter Wheat Seedling Induced by Nickel

用透射电镜观察了镍化合物对蚕豆和冬小麦根端细胞超微结构的影响，结果表明，硫酸镍不同程度地引起蚕豆和冬小麦细胞的损伤。在１５μｇ／ｍｌ浓度下，镍化合物可诱导蚕豆根端细胞核变形，液泡内有凝聚物断续性附着于液泡膜内侧。在相同浓度下，硫酸镍对冬小麦根端细胞内部结构影响较小。在８０μｇ／ｍｌ浓度下，冬小麦细胞液泡有凝聚性变化，质壁有轻度分离。而蚕豆在此浓度处理下，核固缩，核膜崩解，细胞内部电子密度明显升高，结构呈凝聚状，欠清晰，液泡出现凝聚性变化，质壁出现重度分离。以上结果意味着镍化合物对蚕豆的损伤程度要高于对冬小麦的损伤程度。

Effects of nickel on the ultrastructural changes were studied in the broad bean and winter wheat seedling cells, Accompanying nickel uptake, the damage of root-tip cells was examined in both broad bean and winter wheat seedling in varying degrees. Change of nucleus shape, separation of cell membrane and wall were observed in the root-tip cells of broad bean exposed to 15μg/ml NiSO4 for 4 days. A condensed substance appeared on the inner membrane of vacuole intermittently or inside vacuole. Under the condition of same treatment concentration,no significant changes were observed in the root-tip cells of winter wheat seedling. After treatment with 80 μg/ml NiSO4 for 4 days, the vacuole showed irregular shape. A condensed substance inside vacuole,separation of cell membrane and wall were obsrerved in the root-tip cells of winter wheat seedling. But at this concentration, broad bean was found to be more sensitive to nickelinduced damage than winter wheat seedling.Disintegration of nucleus membrane,condensation of nucleus, severe separation of cell membrane and wall, and increase of electron density for the cytoplasm were observed within root-tip cells of broad bean.