百草枯对土壤中蛋白酶和过氧化氢酶活性影响研究

［目的］研究百草枯对土壤中蛋白酶和过氧化氢酶活性的影响。［方法］设4个百草枯处理水平，分别于培养2、6、12、20、30、45和60 d时取样测定蛋白酶和过氧化氢酶的活性。［结果］1 000 μg/g百枯草处理的酶活性低于其他4个处理。100 μg/g百枯草处理的蛋白酶活性的最低值出现在第20天，其余3个百草枯处理的蛋白酶活性的最低值均出现在第12天。1 000 μg/g百枯草处理的蛋白酶抑制率在第20天达51.08%，在第60天为41.48%。200、500和1 000 μg/g百枯草处理均不同程度地抑制过氧化氢酶活性，且其抑制作用随着百草枯浓度的增加而增强。1 000 μg/g百枯草处理对过氧化氢酶的抑制率在第12天达66.18%，在第60天为39.18%。［结论］百草枯对土壤中蛋白酶和过氧化氢酶的活性有较大的影响。

Response of Protease and Catalase in Soil to Paraquat

[Objective]The purpose was to study the influences of paraquat on the activities of protease and catalase in soil.[Method] Four treatment levels of paraquat were designed and the activities of protease and catalase in soil samples cultured for 2, 6, 12, 20, 30, 45 and 60 d were determined.[Result] The enzyme activity in the treatment with 1 000 μg/g paraquat was lower than that in the other 4 treatments. The lowest value of protease activity in the treatment with 1 00 μg/g paraquat occurred on the 20th day and that in the other 3 treatments with paraquat occurred on the 12th day. The inhibitory rate on protease in the treatment with 1 000 μg/g paraquat was up to 51.08% on the 20th day and was 41.48% on the 60th day. All the treatments with 200, 500 and 1 000 μg/g paraquat inhibited the activity of catalase to different extents and their inhibition effects were enhanced as the concn. Of paraquat was increased. The inhibitory rate on catalase in the treatment with 1 000 μg/g paraquat was up to 66.18% on the 12th day and was 39.18% on the 60th day.[Conclusion] Paraquat had relatively great influence on the activities of protease and catalase in soil.