萘胁迫对金鱼藻生理特性的影响

为探讨NAP(萘)对金鱼藻的毒性及其机理,采用1/10Hoagland营养液水培法,研究了ρ(NAP)分别为1.25、2.5、5、10、20和40mg/L下金鱼藻中w(叶绿素)、w(可溶性蛋白)、w(GSH)(GSH为还原型谷胱甘肽)、MDA(丙二醛)含量及SOD(超氧化物歧化酶)和POD(过氧化物酶)活性的变化. 结果表明,在ρ(NAP)为1.25和2.5mg/L时,金鱼藻的各项生理活动与对照组基本没有显著差异(P>0.05). ρ(NAP)越高,对金鱼藻的毒性越大,当ρ(NAP)达40mg/L时,金鱼藻的生理活动受到显著影响(P<0.05). 在胁迫后期(第5、7天),随着ρ(NAP)的增加,w(叶绿素)、w(可溶性蛋白)以及SOD活性均有不同程度的下降,同时w(GSH)和MDA含量上升,膜脂过氧化加剧. 说明w(叶绿素)、MDA含量和SOD活性等是金鱼藻对萘胁迫较为敏感的参数,能表征萘胁迫的毒性. 

Effects of Naphthalene Stress on the Physiological Characteristics of Ceratophyllum demersum

In order to study the toxicity mechanisms of naphthalene (NAP) on Ceratophyllum demersum, 1/10Hoagland nutrient solution hydroponics was used in this study. The contents of chlorophyll, soluble protein, glutathione (GSH ) and malondialdehyde (MDA), and the activities of superoxide dismutase (SOD) and peroxidase (POD) in C. demersum were investigated under the treatments of six NAP concentrations (1.25,2.5,5, 10,0and 40mg/L). Results showed that there was no difference on all measured characteristics for C. demersum with the concentrations of 1.25and 2.5mg/L NAP (P>0.05). However, the physiological activity of C. demersum was affected significantly (P<0.05) as the concentration of the NAP reached 40mg/L. At the late stage (the fifth and seventh days) of NAP stress, as NAP concentration increased, the contents of chlorophyll, soluble protein and the activity of SOD decreased, while GSH and MDA increased which indicated the increases of lipid peroxidatio. Thus, the contents of chlorophyll, MDA, and the activities of SOD could be characterized the toxicity response of C. demersum to NAP.