汞、砷复合污染对水稻生长及吸收汞、砷的影响

在温室条件下,采用水培方法研究汞、砷复合污染对水稻的生长及对汞、砷吸收的影响.实验结果表明:1)汞、砷复合污染可以显著地降低水稻生物量,汞、砷具有显著的交互作用.2)营养液中汞浓度大于0.5mg·L-1时,可显著降低水稻光合速率、二氧化碳气孔导度、蒸腾速率(p<0.001),而砷的影响不显著.3)随营养液中汞浓度的增加,水稻根部和地上部汞含量显著增加,砷对水稻吸收汞的影响不显著,二者无交互作用.随营养液中砷浓度的增加,砷在水稻根部和地上部的累积显著提高,营养液中的汞显著抑制了水稻根部对砷的吸收,二者表现为拮抗作用;而汞对砷在水稻地上部累积的影响则较复杂,随着汞浓度由0.5mg·L-1增加到1.5mg·L-1,水稻地上部砷含量表现出先降低再升高的趋势.

Effects of Combined Contaminations of Mercury and Arsenate on Growth, Hg and As Uptake of Rice (Oryza sativa L.) Seedlings in Solution Culture

A hydroponic experiment was carried out under greenhouse condition to investigate the interactions between Hg and As in the uptake process. The data indicated that combined contaminations of Hg and As have significantly reduced rice biomass. Significant interaction was observed between Hg and As. Photosynthetic rate,stamatal conductance of CO2,transpiration rate were significantly reduced by Hg(p < 0.001) but not As. Both Hg and As had significant effect on As concentrations in roots and shoots(p < 0.001). As concentrations in roots and shoots increased significantly with increasing As concentrations in nutrient solution. Moreover,increasing Hg concentration in the solution significantly reduced As concentration in roots but not in shoots.