沈阳浑河水对玉米耐受和积累重金属Cd的影响

Accumulation of Cadmium in Maize and Tolerance of Maize on the Metal Under Irrigation with Polluted Hunhe River Water

土壤重金属污染和水体富营养化是环境污染中两个重要的方面。浑河水中富含氨氮和磷,氨氮最高达30 mg.L-1以上,磷达0.6 mg.L-1以上,这两项的污染等级均达到Ⅴ级,污染程度为极严重。研究结果表明富营养化的浑河水可促进玉米对重金属Cd的耐受性,在Cd相对含量与对照植株(浇普通淡水)相近的情况下,由于浑河水浇灌的植株生物量较对照高2倍以上,因此,Cd积累的绝对量也提高了2倍多。通过调节浑河水pH,其作用效果进一步加强。探究了浑河水促进玉米植株对Cd耐受的可能机理,结果显示耐受性的提高与抗氧化酶活性的变化有关。浑河水通过诱导玉米细胞内的超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性而使植株对Cd的耐受性增强。由于浑河水使玉米植株内Cd的绝对含量显著增加,我们认为有可能利用浇灌浑河水而使植物更有效地修复重金属污染的土壤,同时又可消除浑河水的富营养化。

We studied a test to use seriously polluted Hunhe River water that is characterized by heavily eutrophication, to irrigate maize. It has been discovered that the water did promote the corn＇s tolerance to heavy metal Cd, in comparison with the control. In addition, the biomass for the treated plots was 2 times higher than the control test, while the content of Cd in maize enhanced more than 2 times, too. It may be concluded that through adjusting Hunhe River water＇ s pH, its function is likely further strengthened. Furthermore, we probed the mechanism of the tolerance of maize towards Cd, and found that the endurance is possibly related to the activity of the change of several kinds of antioxidases. The Hunhe River water through inducing superoxide dismutase （SOD）, peroxicase （POD） and catalase （CAT） activeness in the corn cell to enhance the plant＇ s tolerance to Cd. Because the Hunhe River water causes the absolute content of Cd in the corn increases remarkably, we thought may has the possibility to use water in the Hunhe River to irrigate in order to cause the plant to effectively repair the heavy metal polluted soil, simultaneously may eliminate the water＇s pollution.