除草剂百草枯对蓝藻和绿藻的毒性

Effects of paraquat on the growth of cyanobacteria and green algae

为评估除草剂百草枯对藻类生态系统的环境毒害效应,测定了百草枯对4株蓝藻:铜绿微囊藻(M.aeruginosa XW01,M.aeruginosa 7806)、平裂藻(Merismopedia sp.)、集胞藻(Synechocystis PCC6803),以及两株绿藻:蛋白核小球藻(Chlorella pyrenoidosa)和绿球藻(Chlorococcum sp.472)的毒害效应.采用半效抑制浓度EC50值、无观察效应浓度(NOEC)、最低观察效应浓度(LOEC)及慢性值(ChV)评价了百草枯对6株藻的毒性.结果表明:蓝藻对百草枯的敏感性显著大于绿藻,蛋白核小球藻的96h-EC50值是铜绿微囊藻XW01的96h-EC50值的7.4倍.百草枯毒害作用具有时间效应,暴露时间越长,毒害作用越强.

To assess the toxic effects of herbicide paraquat （1,1＇-dimethyl-4,4＇-bipyridinium dichlorine） on the algal ecosystem, the growths of four cyanobacterial strains （Microcystis aeruginosa XW01, M. aeruginosa PCC7806, Merismopedia sp., and Synechocystis PCC6803） and two green alga strains （Chlorella pyrenoidosa, Chlorococcum sp.472） were measured with different concentrations of paraquat. The Median Effect Concentration （EC50）, Lowest Observable Effective Concentration （LOEC）, No Observable Effective Concentration （NOEC） and Chronic Value （ChV） of paraquat to the six strains were calculated. The experimental results showed that cyanobacteria were more sensitive than green algae to paraquat, and 96 h-EC50 value of C. pyrenoidosa was 7.4 times higher than the value of M. aeruginosa XW01. Longer exposure time displayed higher toxicity.