Abstract: The toxicity effects of glufosinate ammonium to Tetrahymena thermophila were investigated from the viewpoints of cell proliferation and DNA damage. The growth curves of 96 hours were plotted by counting the cells every 12 hours; the tail length, tail moment and Olive tail moment of Tetrahymena thermophila were measured by Single Cell Gel Electrophoresis (SCGE). The results of growth curve test showed that there was a significant difference between drug groups and control group in cell density (P＜0.01). According to SCGE data, the tail length, tail moment and Olive tail moment of the tested series were all significantly larger and higher than those in the control group (P＜0.01), the DNA damage level was higher when toxic compound become heavier (P＜0.01). The experimental concentration of glufosinate ammonium caused damages of cell DNA in varied extents, which reflects the acute and genetic toxicity of it to Tetrahymena thermophila .

Key words: Tetrahymena thermophila, glufosinate ammonium, growth curve, comet assay, DNA damage