中文摘要：

采用水培法研究了土霉素（OTC）暴露对小麦（Triticum aestivum Linn．）生长和根际微生物群落结构的影响。结果表明，在设定的土霉素浓度下，小麦发芽率受抑制程度与处理浓度呈正相关，最大抑制率出现在处理浓度为100mg／L时，达40％；土霉素对小麦根长和芽长的抑制效应显著（P〈0．05），时间和剂量效应明显。PCR—DGGE分析结果表明，0．8mg／L和4．0mc／L土霉素暴露对根际微生物群落结构影响较小,浓度在20．0mg／L以上对微生物群落结构影响显著，出现新的优势种群。

英文摘要：

In this study, the effects of oxytetracychne（OTC） exposure on wheat（Triticum aestivum Linn.）growth and the micro- bial community structure in the rhizosphere were investigated under hydroponic culture conditions.The results showed that the germination of wheat seeds was sensitive to OTC, the inhibition rate was positive correlation with setting OTC concentrations, and the highest rate reached to 40% when exposed to 100 mg/L OTC.The elongation of wheat shoots and roots was significantly （P〈0.05）inhibited by OTC,and there was a good time and dose-response relationship between the OTC concentration and inhibition rates.PCR-DGGE analysis indicated that the bacterial community structure was significantly different in samples that were exposed to high levels of OTC （over 20.0 mg/L） than in samples that were exposed to lower concentrations. As the concentration of OTC increased, some resistant species appeared.