土壤不同浓度铜对小飞蓬毒害及耐受性研究

Responses of Conyza canadensis to different concentrations of copper in soil

通过对高Cu污染区(Ⅰ)、低Cu污染区(Ⅱ)和非污染区(Ⅲ)小飞蓬盆栽实验及生理生化指标分析,结果表明,生态型Ⅰ、Ⅱ、Ⅲ电导率均随着Cu浓度增加而增大,并且两者之间呈极显著正相关;叶绿素(a+b)含量随着Cu浓度增加呈极显著负相关;生态型Ⅰ的蛋白质和脯氨酸含量随着Cu浓度增加均先有所升高,然后又降低,而生态型Ⅱ、Ⅲ则一直呈现降低趋势.3种生态型小飞蓬体内SOD、POD、CAT酶活性在Cu胁迫下均有所提高,与对照相比,当Cu浓度为12 0 0mg·kg-1时,生态型Ⅰ的SOD、POD、CAT活性分别为194. 1%、2 0 6 . 2 %、118 6 % ;Ⅱ的SOD、POD、CAT活性分别为170 . 1%、182 . 9%、111 3% ;Ⅲ的SOD、POD、CAT的活性分别为115. 1%、15 5 . 4 %、10 .7 3% .对3种生态型小飞蓬的生理生化指标及酶活性分析表明,高Cu污染区小飞蓬的耐受性要强于低Cu污染区,两者又均强于非污染区小飞蓬,这3种生态型小飞蓬的耐受性呈现出了明显的种间差异.

Through pot experiment and physiological-biochemical analysis,the study showed that the electric conductivities of Conyza canadensis collected from heavy Cu pollution (Ⅰ),light Cu pollution (Ⅱ) and control (Ⅲ) sites were enhanced,while the chlorophyll (a+b) contents were reduced with increasing Cu concentration.The protein and proline contents in Ⅰ were increased at first and then reduced,but those in Ⅱ and Ⅲ were reduced with increasing Cu concentration.The activities of SOD,POD and CAT were intensified under Cu stresses.When the Cu concentration was 1 200 mg·kg~ -1,their activities in Ⅰ,Ⅱ and Ⅲ were increased 194.1%,206.2% and 118.6%,170.1%,182.9% and 111.3%,and 115.1%,155.4% and 107.3%,respectively,in comparing with the control,which illustrated that the tolerance of Conyza canadensis was in order of heavy Cu pollution site>light Cu pollution site >control site,and the three ecotypes showed distinct differences in tolerance.