EFFECTS OF CIPROFLOXACIN-OXYTETRACYCLINE COMPOUNDS ON TOBACCO SEEDLING GROWTH IN HYDROPONICES

Tobacco leaf quality matter its value but is easily influenced by environmental factors, such as antibiotics, which reside in soil by utilization of manure. Experiments were conducted by adding ciprofloxacin (CIP) and oxytetracycline (OTC) compounds to hydroponic tobacco seedlings with three varieties, Honghua Dajinyuan (HD), Yunyan87 (Y87) and K326, and their growth was observed. Results showed that concentration of chlorophyll a decreased by 83.33%, 88.36% and 87.59% in HD, Y87 and K326 at 60 mg L -1 CIP+60 mg L -1 OTC treatment. Aboveground fresh weight decreased from 1.24 g to 0.2 g in HD, from 0.53 g to 0.25 g in Y87 and from 0.83 g to 0.38 g in K326 at 60 mg L -1 CIP+60 mg L -1 OTC treatment. With increasing antibiotic concentrations, CIP was accumulated from 1.33 to 1.56 µg g -1 in Y87 and from 4.66 to 7.98 µg g -1 in K326, and OTC was accumulated from 0.54 to 0.84 µg g -1 in Y87 and from 3.30 to 5.53 µg g -1 in HD. With increasing antibiotic concentrations, chlorophyll and carotenoid contents, root activity, enzyme activity and fresh weight decreased significantly, and more antibiotics accumulated from 0.54-7.98 µg g -1 differently in all three varieties of tobacco. Comparing experiment results it suggests that chlorophyll and carotenoid contents and aboveground fresh weight decreased less in Y87, and it accumulated less antibiotics as well. Y87 could grow better and accumulate less antibiotic compared with the other two varieties.