单一重金属胁迫对灯心草生长及生理生化指标的影响

通过盆栽试验研究了不同浓度处理水平的Cu、Cd、Pb、Zn、As五种重金属单一胁迫对灯心草生长及其生理生化特性的的影响。结果表明:种植灯心草土壤中的Cd、Pb、Cu三种重金属临界值可分别设定为10mg kg-1、100 mg kg-1、100mg kg-1。灯心草不适合在Zn污染的土壤中种植,土壤中As临界值尚需作进一步的研究来确定。各单一重金属胁迫对灯心草叶绿素的合成均有很大程度的抑制作用,剂量-效应关系明显。灯心草三种保护酶对于不同浓度处理水平重金属胁迫的响应不同:在土壤环境质量低浓度设置范围内三种酶有较好的协同效应能共同抵御重金属胁迫造成的膜伤害,表现出较强的自我调节能力。而在高浓度处理水平时,三种酶活性呈现不同的变化趋势。灯心草生理生化指标对重金属胁迫的响应存在元素种类之间的差异。各单一重金属对灯心草生长抑制及生理毒害效应大小排序为:Zn>As>Cu>Pb>Cd。

Effects of Cu, Cd, Pb, Zn and As Single Stress on the Hrowth and Physiological and Biochemical Characteristics of Juncus Effuses

The effect of Cu,Cd,Pb,Zn and As on the growth and the physiological and biochemical characteristics of Juncus Effuses were studied by pot experiments.The results showed that the critical values of Cd,Pb,and Cu in the Juncus Effuses grown soil were set at 10,100 and 100mg kg-1 respectively,but Juncus Effuses was not able to grow in the Zn polluted soil.The critical value of As in soil should be studied further.When the treatment concentration of different heavy metals increased,the synthesis of chlorophyll in Juncus Effuses was inhabited greatly and there was obvious dosage and while the response of three defensive enzymes in Juncus Effuses was different to heavy metal concentrations.The findings indicated that the response of physiological and biochemical index of Juncus Effuses was different to different heavy metals.