重金属镉对红树植物白骨壤和桐花树幼苗生理特性的影响

通过砂泥栽培实验研究了红树植物桐花树和白骨壤幼苗在含Cd 0.6～30 mmol·L~(-1)系列海水培养液中某些生理特性的变化。当培养液中Cd浓度为0.6 mmol·L~(-1)时桐花树和白骨壤幼苗生长正常,叶绿素含量和光合速率变化不大。当高于12 mmol·L~(-1)时,除桐花树和白骨壤幼苗除POD酶活性越来越高之外,叶绿素含量、光合速率、SOD、CAT酶活性均不断减弱,而且浓度愈高,这些指标下降愈大。结果表明Cd对红树植物桐花树和白骨壤幼苗具有毒害作用,Cd浓度愈高对其毒害愈严重,两种红树植物比较,桐花树抗重金属镉毒害的能力大于白骨壤。

Effect of Cadmium on physiological characteristics of mangrove Avicennia marina and Aegiceras corniculatum seedlings

Based on the pots experiments in sand and mud culture,the effect of heavy metal Cd on some physiological characteristics of Avicennia marina and Aegiceras corniculatum mangrove seedlings were studied when treated by saline water with different concentrations of Cd(0.6—30 mmol·L~(-1)).The results indicated that at the concentration of 0.6 mmol·L~(-1),the chlorophyll content and the photosynthetic rates of Aegiceras corniculatum and Avicennia marina seedlings remained unchanged,the mangrove seedlings also grew well.When Cd concentration was higher than 12 mmol·L~(-1),the leaf chlorophyll content and activities of POD and SOD in Avicennia marina and Aegiceras corniculatum seedlings began to decrease.But as the increasing of the concentration of Cadmium the activity of POD got lower and lower. The results were showed that Cd had poisoning effect to mangrove;higher Cd concentration could lead to more serious poisoning effect.Comparing the two terms,Aegiceras corniculatum had a higher tolerance to Cd than Avicennia marina.