三种蔬菜对水中四环素的吸收累积效应

为了进一步了解抗生素在土壤—蔬菜系统中的迁移过程与规律,以四环素(tetracycline,TC)为目标抗生素,采用水培蔬菜的方式,通过测定根际暴露24 h内上海青、木耳菜和大白菜叶中TC含量的变化,计算叶的TC累积速率;对比根际暴露24 h后TC在植物体不同部位中的含量分布,研究了TC的迁移规律。结果表明,水溶液中的TC能够被蔬菜根部快速吸收并传输到叶片,根际暴露1 h内即可在叶中检出较高含量的TC,且3种蔬菜叶中TC的累积速率随暴露时间增加而降低。蔬菜对TC的吸收累积能力与种类有关,试验条件下木耳菜对TC的吸收和传输能力均远大于大白菜和上海青。根部在蒸馏水和根际液配制的含TC营养液中分别暴露24 h后,上海青根中TC含量大于叶中含量,而木耳菜和大白菜叶中TC含量均大于根,植物根际分泌物可能影响TC向植物中迁移。

The Absorption and Accumulation Ability of Three Kinds ofVegetables on Tetracycline in solution

To understand the migration processes and rules of antibiotics in the soil-plant system further,measuring the change of tetracycline (TC) by three kinds of vegetable (pakchoi, malabar spinach andChinese cabbage) which cultivated with nutrient solution within 24 hours. Calculating the accumulation rateof TC in leaves. Comparing concentration distribution of TC in different parts of vegetable after rhizosphereexposurein in 24 h, and the migration of TC was studied. The results showed that TC in solution couldbe absorbed by vegetable roots and be transported to leaves quickly, high concentration of TC could bedetected after 1 hour root exposure to nutrient solution within TC in three kinds of vegetable leaves, andthe accumulation rates of TC were decreased with time increasing in three kinds of vegetable leaves. Afterroot exposure to nutrient solution with TC for 24 hours, malabar spinach was more efficient in TC uptakeand translocation than pakchoi and Chinese cabbage, the accumulating ability was connected with species.When TC nutrient solution contaminated with TC were prepared with distilled water or rhizosphere solution,the concentration of TC in different parts of pakchoi were: root>leaf after root exposure for 24 hours; while the concentration of TC in leaves was greater than roots to Chinese cabbage and malabar spinach. The rootexudate may affect the migration of TC to plants.