摘要
用不同浓度Hg2+、Cd^（2+）溶液培养沉水植物轮叶狐尾藻植株,比较研究重金属离子对其生理指标及超微结构的影响.Cd^（2+）污染时,轮叶狐尾藻叶片、茎出现黑色斑点,而受Hg^（2+） 污染时均匀褪绿,未出现斑点.Hg^（2+） 、Cd^（2+）污染均使轮叶狐尾藻叶片叶绿素含量减少,较低浓度时,光合速率、呼吸速率、过氧化物酶活性及可溶性蛋白含量上升,随着污染物浓度的加大、污染时间的延长,则导致其相应生理指标下降.电镜结果显示:叶细胞受Hg^（2+） 、Cd^（2+）毒害后,染色质呈凝胶状,膜系统解体,核糖体消失.研究表明,在相同处理浓度和时间条件下,Hg^（2+） 毒性较Cd^（2+）强,Hg^（2+） 对轮叶狐尾藻的快速致死浓度为1~2mg/L,Cd^（2+）为3~5mg/L.
Cultivating the Myriophyllum verticillatum Linn with Hg2+ and Cd2+ solutions of different concentrations, the effect of heavy metal on physiological index and ultrastructure of the plant was studied. Under Cd2+ pollution, black spots appeared on leaves and stems of Myriophyllum verticillatum Linn, while under Hg2+ pollution, they have no spots and lost the green color evenly. In both cases, the chlorophyll content of leaves decreased. Lower concentration of Hg2+ and Cd2+ increased chlorophyll content, photosynthesis rate, respiration rate, activity of POD and protein content of leaves, while higher concentration and longer time of pollution decreased their physiological index. Ultrastructural observation showed agglutination of chromatin, disintegration of membrane systems and disappearance of ribosomes after the leave cells were poisoned. The results showed that the toxicity of Hg2+ on Myriophyllum verticillatum Linn was heavier than that of Cd2+ under the same treating time and concentration, and that the quickly lethal concentration of Hg2+ to Myriophyllum verticillatum Linn was 1-2 mg/L and that of Cd2+ was 3-5 mg/L.
出处
《中国环境科学》
EI
CAS
CSSCI
CSCD
北大核心
2001年第4期371-375,共5页
China Environmental Science
基金
国家自然科学基金资助项目(39770046)
江苏省教育厅自然科学基金资助项目(BK97107)
关键词
轮叶狐尾藻
生理指标
超微结构
汞
镉
植物监测
水质污染
毒性
Myriophyllum verticillatum Linn；Hg^（2+） ；Cd^（2+）；pollution；physiological index；ultrastructure
