中文摘要：

纳米材料的生态毒性问题越来越受到人们的广泛关注。本文探讨了纳米氧化铜（22～75nm，平均43nm）对白菜种子发芽的影响，并以微米氧化铜和铜离子（Cu^2＋）进行对比分析。结果表明，各浓度处理（0．2、0．5、1、2．4、8mg·L^-2）纳米氧化铜对白菜种子发芽率与对照相比均无显著差异（P〉0．05），但在较低浓度下（0．4mg·L^-1）对根伸长和芽伸长即表现出抑制作用。随着纳米氧化铜浓度增加，对根伸长抑制率显著提高，对芽伸长抑制率则缓慢提高，其半抑制浓度（IC50）分别为11．4mg·L^-1和1309．4mg·L^-1.100mg·L^-1时，微米氧化铜对白菜根、芽伸长的抑制率都小于20％，其毒性小于纳米氧化铜；但纳米氧化铜的毒性并非其溶解出的铜离子所致。

英文摘要：

Eco-toxicity of nanomaterials was subject to more and more attention recently. The toxicity of copper oxide nanoparticles （22-75 nm, the average 43 nm） to seed germination of Chinese cabbage was investigated, and the counterpart investigation of copper oxide micron particle and copper ions were compared. The results showed that the effect of copper oxide nanoparticles within the concentrations of 0.2, 0.5, 1, 2, 4 mg. L^-1 and 8 mg· L^-1 on seed germination rate of Chinese cabbage showed no significant difference compared with control（P〉0.05 ）, but the inhibitation of root elongation and shoot elongation was obserVed in lower concentrations. With the increasing concentrations of copper oxide nanopartieles, inhibition rate increased significantly for root elongation but slowly for shoot elongation, with half-inhibitory concentration （IC50） of 11.4 mg· L^-1 and 1 309.4mg· L^-1 , respectively. The toxicity of copper oxide nanoparticles was stronger than that of copper oxide micron particle. However the copper ion（Cu^2＋, 0.22 mg· L^-1 ） dissolved from 8 mg· L^-1 of copper oxide nanopartieles contributed to the inhibitation only 4.6% for root elongation and almost zero for shoot elongation.