中文摘要：

选取水体中广泛存在的壬基酚为代表,研究其对四尾栅藻生理特性及群体形成的影响。实验设置6个暴露组（0.63、1.02、1.65、2.67、4.32和7.00 mg·L-1）和1个对照组（0 mg·L-1）,测定了96 h内四尾栅藻细胞密度、叶绿素a含量、胞外多糖合成、最大光能转化效率（Fv/Fm）以及群体形态等变化。结果表明,四尾栅藻起始细胞密度6.64×10^5 cells·m L-1下,壬基酚对四尾栅藻细胞密度的EC50为2.05 mg·L-1;随着壬基酚质量浓度的提高,四尾栅藻的叶绿素a含量和Fv/Fm下降,四尾栅藻的生长受到抑制,但细胞胞外多糖含量增多,导致细胞间黏性增强,同时双细胞和多细胞（≥3个）群体占总细胞比例上升。

英文摘要：

In order to study the physiological effect of nonyl phenol（NP） on fresh algae, Scenedesmus quadricanda was exposed to NP at six concentrations（0.63, 1.02, 1.65, 2.67, 4.32, and 7.00 mg·L-1）, and 0 mg·L-1 of NP was the control. Its cell density, chlorophyll a content, maximum light conversion efficiency（Fv/Fm）, extracellular polysaccharide and cell morphology were measured after exposuring to NP for 96 hours. Results showed that the EC50 of NP to Scenedesmus quadricanda was 2.05 mg·L-1 when the initial cell number was 6.64×10^5 cells·m L-1. With an increase of NP level, the chlorophyll a content and Fv/Fm of microalgae decreased, but the growth of Scenedesmus quadricanda was inhibited and the extracellular polysaccharide content and colony formation were promoted, which would help colony formation and maintainance.