纳米TiO2对油菜种子发芽与幼苗生长的影响

通过纸床培养，研究在不同浸种时间下，不同浓度的10nmTiO2悬浮液对油菜种子发芽及幼苗生长的影响。结果表明：浸泡时间为2h的各指标表现最显著，最适合作为纳米TiO2对油菜种子发芽和幼苗生长影响的浸种时间。浸种2h纳米TiO2的发芽势、发芽率、发芽指数抑制率与纳米TiO2浓度呈显著正相关，与浓度的对数作线性回归得出，IC20分别为1907、619．0、1039mg·L-1；总长、芽长、根长、总重、芽重、根重的激活率与纳米TiO2的浓度呈显著正相关，通过线性回归方程得出总长、芽长、根长、总重、根重的EC20分别为99．77、404．5、55．46、6918、2187mg·L-1。对各指标影响的敏感性大小为：发芽率〉发芽指数〉发芽势，根长〉芽长。因此，油菜发芽率与根长可以作为评价纳米TiO2生态毒性效应的较敏感指标。

Effect of Nano-TiO2 on the Germination and Growth of Rape Seed

The impact of various concentration of nano-TiO2 suspension at different soaking time on the germination and growth of rape seed was investigated. The results showed that 2 hours of soaking time was significantly suitable for these assessments. There were positive corre- lations between the logarithm of the concentrations of nano-TiO2 suspension and the inhibitory rate of seed germination, and the IC20 obtained from the regression equations were 1 907 mg·L-1（germinability）, 619.0 mg·L-1（germination rate）, and 1 039 mg·L-1（ germination index） respectively. On the other hand, there were also positive correlations between the logarithm of the concentrations of nano-TiO2 suspension and the activation rate of the length and weight of root and bud, and the EC20 were 99.77 mg·L-1 （total length）, 404.5 mg·L-1 （ bud length）, 55.46 mg·L-1 （root length）, 6 918 mg·L-1（total weight）, 2 187 mg·L-1（root weight）. It could be concluded that the order of sensitivity among different indexes was germination rate〉germination index〉germinability, root length〉bud length, suggesting that germination rate and root length could be as sensitive indexes for assessing eco-toxicity effectiveness of nano-TiO2.