外源四环素对土壤酶活性和油菜品质的影响

通过向土壤中添加四环素溶液研究种植油菜条件下，不同浓度（0、0.30、0.60、0.90 mg·kg^-1）的外源四环素对土壤酶活性和油菜品质的影响.结果表明：各处理土壤的脲酶与0.90 mg·kg^-1浓度处理的土壤转化酶活性在整个培养期均受到抑制，0.30、0.60 mg·kg^-1浓度处理的土壤转化酶活性则表现为激活-抑制-激活趋势，各处理土壤蛋白酶活性表现为抑制-激活趋势，且土壤酶活性受到外源四环素的影响程度及持续时间与处理浓度呈正相关（r=0.950**）.各处理土壤过氧化氢酶活性在前期被激活，后期差异不明显.四环素对土壤脲酶、过氧化氢酶、转化酶和蛋白酶活性的作用时间分别为：7周、6～8周、7周和6～7周.收获时0.30、0.60、0.90 mg·kg^-1处理的油菜叶片中可溶性糖含量与对照相比分别下降91.99%、87.92%和90.12%，而可溶性蛋白质含量分别上升26.47%、28.13%和23.22%.

Effects of exogenous tetracycline on rape soil enzyme activity and rape quality.

This paper studied the effects of applying different concentration (0, 030, 0 60, and 090 mg·kg-1) tetracycline on the soil enzyme activities and rape quality. The results showed that soil urease activity after applied 030, 060, and 090 mg·kg-1 of tetracycline and soil su crase activity after applied 090 mg·kg-1 of tetracycline were inhibited in the whole cultivating period, while the soil sucrase activity after applied 030 and 060 mg·kg-1 of tetracycline showed a trend of activation-inh ibition-activation. Soil proteinase activity showed a trend of inhibition-acti vation, and the extent and duration of the inhibition and activation had signifi cant positive correlations with tetracycline concentration (r=0950** ). Soil catalase activity showed activation first and turned to irregular then. The action duration of tetracycline on the activities of soil urease, catalase, sucrase and proteinase were 7 weeks, 6〖KG-*2〗-〖KG-*7〗8 wee ks, 7 weeks, and 6〖KG-*2〗-〖KG-*7〗7 weeks, respectively. At harvest time, the soluble sugar contents in rape leaves after applying 030, 060, and 090 mg ·kg-1 of tetracycline decreased dramatically by 9199%, 8792%, 9012% , while the soluble protein content increased by 2647%, 2813%, and 2322%, respectively, compared to the control.