Welcome to Chinese Agricultural Science Bulletin,

Chinese Agricultural Science Bulletin ›› 2014, Vol. 30 ›› Issue (17): 272-278.doi: 10.11924/j.issn.1000-6850.2013-2193

Special Issue: 生物技术 土壤重金属污染

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Individual and Complex Effects of Cd2+;Cr6+ on the Physiological Characteristics of Spirodela oligorrhiza

  

  • Received:2013-08-16 Revised:2013-09-23 Online:2014-06-14 Published:2014-06-14

Abstract: To understand the toxicity mechanisms of mixed heavy metals on aquatic plant, ndicators of the content of chlorophyll, the activity of SOD, POD and the content of MDA in leaves of Spirodela oligorrhiza, hydroponic experiments were conducted in this study for exploring the biological responses of Spirodela oligorrhiza leaves to single and joint stress of Cadmium (Cd) and chromium (Cr6+ ). The results showed that single- Cd treatment had significant influences on the content of chlorophyll. With the increase of Cd concentrations, the content of chlorophyll decreased evidently, the stress content of chlorophyll is a sensitive index in response to the Cd-pollution. With the increase of Cd concentrations, the Spirodela oligorrhiza leaf SOD and POD activities appeared as an increasing- decreasing trend, and POD activities higher than CK. While the content of MDA increased persistently. Chromium (Cr6+) single treatment on Spirodela oligorrhiza indicators influence were similar to Cd, but were less than Cd. Under the Cd-Cr6+ combined stress, the content of chlorophyll decreased with increasing contentration, and less than the single-Cd stress. But there was no striking concentration difference of chlorophyll between groups of different Cr6+ concentrations in the same cadmium concentration, which showed that Cd2+ was dominant in the destruction of chlorophyll, the Spirodela oligorrhiza leaf SOD and POD activities appeared as an increasing- decreasing trend, but these enzyme activities decreased when compared with the single-Cd stress, and POD activities lesser than CK; the content of MDA increased with increasing concentration, and higher than the single-Cd stress, which suggested that the combined toxicity of Cd and Cr6+ was stronger than the single-Cd stress. The interaction of Cadmium and Chromium showed synergism action.