[Objective] Antibiotics are extensively given to livestock to promote its growth and reduce its diseases.Therefore,antibiotics may be present in manure and slurry from their parent compound and/or metabolites.The soil environments may be exposed to these antibiotics due to the application of animal manure to agricultural land.So,in this study,accumulation and phytotoxicity indicators were analyzed to evaluate the effects of oxytetracycline （OTC,C22H24N2O9HCI） on vegetable crop.[Method] A pot experiment was conducted in the greenhouse,radish plant （Raphanus sativus L.） was grown for seven weeks in two soils （sand soil and clayey soil） that were amended with pig manure and spiked with six levels （0,2,5,10,25 and 50 mg per kg of soil） of oxytetracycline for observing the potential effects of long-term application of antibiotics-contained animal manure on plant growth and determining whether or not radish plant grown in manure-applied soils absorbs OTC present in the soils.Contents of oxytetracycline in both root and shoot tissues were determined,and effects of soil oxytetracycline pollution on photosynthesis and biomass of the plant were monitored.[Result] The results showed that radish plant can absorb OTC from the soils.The concentration of OTC in plant tissues increased with increasing the concentration of OTC present in the soils,and was higher at the initial growth stage than at last stage of the plant.Higher concentration of OTC was found in roots than shoots of the plant.Bioavailability of OTC in the sandy soil was greater than that in clayey soil.OTC did not affect the growth of the plants when its concentration in the soils was less than 10 mg/kg.However,higher concentration of soil OTC （＞25 mg/kg） caused serious stress in the plant,reducing photosynthetic rate of leaves and biomass of both roots and shoot.[Conclusion] This study points out the potential human health risk associated with consumption of fresh vegetable grown in the soils amended with antibiotic laden manures.
