除草剂草甘膦对中华大蟾蜍的慢性毒性

为揭示除草剂对农林生态系统中脊椎动物天敌潜在的、长期的慢性毒性，测定了草甘膦对中华大蟾蜍（Bufo gargarizans Cantor）蝌蚪生长发育和运动频率的影响以及对中华大蟾蜍成体空胃率的影响。结果表明，亚致死剂量的草甘膦溶液对中华大蟾蜍蝌蚪的生长发育和运动频率具有明显的抑制作用，蝌蚪体长、体宽、尾长、尾宽和体质量的增长率均与草甘膦浓度呈极显著负相关；蝌蚪的运动频率亦与草甘膦浓度显著负相关。同时，草甘膦的喷施对中华大蟾蜍成体的捕食造成负面影响，其空胃率与草甘膦浓度呈极显著正相关，即使在草甘膦的推荐使用浓度范围之内．中华大蟾蜍（成体）处理组亦出现30％～60％的空胃率。

Chronic Toxicities of Herbicide Glyphosate on Bufo gargarizans

For studying the chronic toxicities of herbicides on the vertebrate natural enemy, the effects of glyphosate on the growth rate, motional rate and gastric vacuous rate of Bufo gargarizans Cantor were mesured. The results showed that the sublethal dose of glyphosate obviously affected the growth and movement of the tadpoles and the predation of the adults. The growth rate indexes of the tadpoles, including body length, body breadth, tail length, tail breadth, body weight, etc. , and the motional rate of the tadpoles wre all negatively correlated with the glyphosate concentration. The gastric vacuous rate of the adults, however, was positively correlated with the ghyphosate concentration. There would be 30% -60% Bufo gargarizan adults with no prey in their stomaches even they were sprayed by the ghyphosate in recommended concentration.