重金属镉对沉水植物毒性效应的研究  

Toxicity of Cadmium to Submerged Macrophytes

作　　者：王模善[1] 赵铁铭[1] 

机构地区：[1]北京大学环境科学中心,北京100871

出　　处：《西南大学学报（自然科学版）》2008年第4期128-134,共7页Journal of Southwest University(Natural Science Edition)

基　　金：国家"八五"攻关资助项目(85-908-02-03)

摘　　要：通过观察组织显微结构以及测定植物体内叶绿素和游离脯氨酸含量,研究了镉对3种沉水植物蓖齿眼子菜(Potamogeton pectinatus)、金鱼藻(Ceratophyllum demersum)和轮藻(Chara vulgaris)细胞组织完整性以及碳代谢和抗胁迫能力的毒性效应.结果表明:尽管镉有效地抑制了沉水植物的碳代谢和抗胁迫能力,从而导致组织完整性的破坏和植物死亡,但是这3种沉水植物对镉毒害的抗性却有着明显的不同.凭借其致密的细胞排列、较厚的表皮层以及较高的游离脯氨酸水平,蓖齿眼子菜表现出很强的抗镉毒害的能力.因此建议将其作为水生植物生态系统恢复与重建的先锋物种.Exposure to high levels of the heavy metal cadmium normally results in toxic effects on the aquatic ecosystem and its primary producer-submerged macrophytes. Cadmium toxicity to the three submerged macrophytes of Potamogeton pectinatus , Ceratophyllum demersum and Chara vulgaris was studied through microscopic examination of leaf tissues, determinations of the contents of chlorophylls and free proline under cadmium stress and observation the integrity of cells and tissues, photosynthesis and antistress capacity. The results indicated that high levels of cadmium effectively inhibited photosynthesis and antl-stress capacity of all the 3 species studied, leading to the disruption of the integrity of tissues and death of the plants. However, the three submerged macrophytes varied greatly in their tolerance to cadmium toxicity. Owing to its compact arrangement of the epidermis cells, thick epidermis layer and high free proline levels, P. pectinatus demonstrated a higher resistance to cadmium toxicity than the other two species. Therefore, P. pectinatus is recommended as a pioneer species in restoration and reconstruction of aquatic ecosystems.

关 键 词：镉 蓖齿眼子菜 沉水植物 游离脯氨酸 叶绿素 

分 类 号：Q948[生物学—植物学]