Hg2＋、Cd2＋及其复合胁迫对苦草的毒害  

Stress of Hg^(2+) and Cd^(2+) on Vallisneria natans

作　　者：马剑敏[1] 靳同霞[1] 成水平[2] 贺锋[2] 吴娟[2] 吴振斌[2] 

机构地区：[1]河南师范大学生命科学学院,河南省环境污染控制重点实验室,河南新乡453007 [2]中国科学院水生生物研究所,淡水生态与生物技术国家重点实验室,湖北武汉430072

出　　处：《环境科学与技术》2008年第6期78-81,共4页Environmental Science & Technology

基　　金：国家“十五”重大科技专项(2002AA601021);河南省科技攻关项目(0624440039);淡水生态与生物技术国家重点实验室开放课题(06FB03)

摘　　要：利用微宇宙系统研究了不同浓度的Hg2+、Cd2+单一及复合处理下,苦草对这三种胁迫的响应。三种胁迫下,3d内苦草现存量增加百分比与金属离子浓度间显著负相关,其中在[Hg2+]或[Hg2++Cd2+]([Hg2+]/[Cd2+]=1)>5μmol/L时,2～3d可致死;总生产力、净生产力、呼吸强度以及叶绿素含量均随着金属离子浓度的增加而下降,同时叶绿素含量还随着胁迫时间的延长而降低,但上述四个指标在低浓度胁迫时常略有升高;可溶性蛋白含量在[Hg2+]或[Hg2++Cd2+]≤2.5μmol/L、以及[Cd2+]≤10μmol/L时升高或基本稳定,之后随着金属离子浓度的增加和胁迫时间的延长而明显降低。Hg2++Cd2+的复合胁迫效应略小于相应浓度的Hg2+,但明显大于相应浓度的Cd2+。Hg2+对苦草的毒性数倍于Cd2+,二者对苦草的毒性有相加或协同效应。Stress of heavy metals such as Hg2＋ and Cd2＋ on a common submerged plant, i.e., Vallisneria natans is studied in terms of standing crop, productivity, respiration, chlorophyll content and dissoluble protein content. The percentage of increased standing crop is notably negative correlated to concentrations of heavy metals under stress of Hg2＋ and Cd2＋ respectively as well as Hg2＋ and Cd2＋ combined. It has been showed that Hg＋ and Cd2＋ combined stress is weaker than the single Hg2＋ , but much stronger than the single Cd2＋.

关 键 词：Hg2+ Cd2+ 急性胁迫 苦草 

分 类 号：X503.23[环境科学与工程—环境工程] X171.5