Ecotoxicity of Chloramphenicol and Hg Acting on the Root Elongation of Crops in North China

Single and joint toxicity of chloramphenicol and Hg acting on wheat (Triticum aestivum L.), Chinese cabbage (Brassica campestris L.) and corn (Zea mays L.) were investigated. The results showed positive correlations between root elongation inhibition of three plants and concentrations of pollutants added to soil (P<0.01) in test concentration range. In terms of root elongation, wheat was the most sensitive to toxicity of chloramphenicol with an IC50 (concentration when 50% plants show inhibition) value as high as 26.8 mg/kg and also was the most sensitive one to the toxicity of Hg with the IC50 value as high as 300.8 mg/ kg. The toxicity of chloramphenicol to the plants is stronger than that of Hg. Chloramphenicol and Hg had an antagonistic effect on the inhibition of root elongation of the three plants when the concentration of added Hg reached 30 mg/kg. Chloramphenicol and Hg had significantly synergistic effects on the inhibition of root elongation when Hg concentration was up to 200 mg/kg (P<0.05).