土霉素对不同生长期青菜生长的影响及其在青菜地上部分的积累

Phytotoxicity and Accumulation of Oxytetracycline from Soil in Chinese Cabbage(Brassica chinensis var. chinensis) with Different Growing Stages

为了解土霉素对不同生长期青菜生长的影响及不同生长期青菜对土壤中抗生素吸收能力的差异,用盆栽土培试验研究土壤中土霉素（污染水平为0～30 mg/kg之间）对不同生长期青菜生长状况及其对土壤中土霉素吸收的影响。结果表明,在研究的土霉素污染范围内,土霉素污染水平对青菜种子发芽率、营养生长盛期和成熟期的生长影响不明显;但当土霉素污染水平在10、30 mg/kg时对青菜幼苗期根系伸展、地上部茎高及生物量产生显著的影响。在土霉素添加20天后的青菜地上部分中积累的土霉素含量以在营养生长盛期和出苗—幼苗期施用土霉素者为较高;而对于生长60天后收获的青菜的地上部分土霉素残留含量则随土霉素添加时间至收获时间间隔变短而增加,并随土壤中土霉素污染水平的增加而增加。结果认为,青菜生长在前期比后期更易受抗生素污染的毒害,而对于收获的青菜中积累的抗生素含量在后期受抗生素污染者比前期抗生素污染者更易积累。

In order to understand the phytotoxicity and accumulation of oxytetracycline from soil in Chinese cabbage（Brassica chinensis var chinensis） at different growing stages, a pot soil culture experiment was conducted to study the toxicological effects of oxytetracycline pollution（at concentrations ranging from 0 to 30 mg/kg） on the growth of Chinese cabbage and uptake of oxytetracycline by the plant. The results showed thatsoil oxytetracycline pollution with concentrations of 〈30 mg/kg had no significant effects on seed germinationand plant growth of Chinese cabbage at the vegetative and mature growing stages of the crop. However, at pollution levels of 10 and 30 mg/kg, oxytetracycline had significant effects on root elongation, shoot length, and biomass of vegetable seeding. Accumulations of oxytetracycline in aboveground compartment of the plant at 20 days after application of the antibiotics were relatively higher at the seed emergence or vegetative growing stages than that at mature growing stage. And for plant harvested 60 days after seed sowing, residues of the antibiotics in the plant increased with decreasing of the time interval from addition of oxytetracycline to plant harvest. The residues increased with increasing pollution levels of oxytetracycline in the soil. The results suggested that the plant growth at earlier stage was more susceptible to antibiotics pollution than that at later stage. Accumulation of antibiotic in harvested plant was higher in plant polluted by antibiotics at later stage than that polluted at earlier stage.