Objectives]The aim of this study was to investigate efficiency of sunf1ower ’s Phytoremediation in coPPer-contaminated soi1 under different CO2 concentration 1eve1s and various che1ating agents. Furthermore,this study aimed to screen CO2-sensitive cu1tivars of sunf1owers,therefore,Providing data to suPPort the need for Phytoremediation of coPPer-contaminated soi1.[Methods]A Pot exPeriment was conducted in artificia1 c1imate chambers under two CO2 concentration 1eve1s,norma1(370 μmo1/mo1)and e1evated(800 μmo1/mo1). Using a comP1ete1y randomized design,five different cu1tivars of sunf1owers in soi1 contaminated with 100 mg/kg Cu were treated with different concentrations of EDTA and DTPA to determine the effects of a che1ating agent in combination with various 1eve1s of CO2 concentration on rePair efficiency of sunf1owers in Cu-contaminated soi1.[Results]1)The extraction of Cu from the contaminated soi1 using different che1ating agents is significant1y different. Based on the 1ow toxicity fo11owed by high concentration of che1ate when extracting Cu from contaminated soi1,EDTA 3 mmo1/kg soi1 and DTPA 5 mmo1/kg soi1 are se1ected. 2)The 1oss of green in 1eaves and dehydration of sunf1owers are re1ieved to some extent under the e1evated CO2 concentration fo11owing the aPP1ication of che1ating agents. Furthermore,the tota1 biomass amounts of Shikui-3 and A1tai-2 are increased,whi1e those of Shikui-4 and A1tai-1 are decreased. 3)Soi1 PH va1ues are increased in the treatments with che1ating agents at both CO2 concentrations, and the extent of the increase in the DTPA treatments is significant1y higher than that in the EDTA treatments. A1though the e1evated CO2 concentration has an imPact on soi1 PH,there was no significant difference in soi1 PH between the two CO2 1eve1s for the five sunf1ower cu1tivars. 4)The above-ground Cu accumu1ation in Shikui-4 and A1tai-1 significant1y decreased under conditions of e1evated CO2. The Cu accumu1ation amounts in shoots of Shikui-3 and Youshengyin-2 are s1ight1y increased under conditions of e1evated CO2 ,whi1e the amount in shoots of A1tai-2 is significant1y increased. The Cu concentrations of sunf1ower 1eaves and stems in the treatments with 5 mmo1/kg soi1 DTPA under e1evated CO2 conditions are increased by 239% -646% comPared with the contro1s,and the Cu accumu1ation amounts of the P1ants are increased by 230%-362%. The resu1ts a1so show that the effect of Cu concentrations in stems and 1eaves of sunf1owers are consistent. The mobi1ization of Cu in soi1s is more active in the DTPA treatments comPared with the EDTA treatments.[Conclusions]Sunf1ower resistance to Cu can be enhanced to some extent under conditions of e1evated CO2. A1tai-2 is the most sensitive to e1evated CO2 in 100 mg/kg Cu-contaminated soi1. It is Possib1e that the aPP1ication of che1ating agents is a main factor of affecting the soi1 PH change under conditions of e1evated CO2 . The DTPA 5 mmo1/kg treatment is more effective in the remediation of Cu-contaminated soi1(100 mg/kg)under the e1evated CO2 condition comPared with EDTA 3 mmo1/kg.%【目的】以向日葵为研究材料，探讨其在CO2浓度升高条件下修复铜（ Cu）污染土壤的效率以及对比CO2与螯合剂联合诱导下向日葵对铜污染土壤修复效率的差异，并筛选出对CO2浓度升高响应显著的品种，以期为利用植物修复铜污染土壤提供数据支撑。【方法】在设置两个CO2浓度的人工气候室内（正常浓度370μmo1/mo1和升高浓度800μmo1/mo1），采用完全随机设计的盆栽土培试验，通过5个不同品种的向日葵，向铜污染水平为100 mg/kg的土壤上施加不同浓度EDTA和DTPA，研究CO2浓度与螯合剂联合施用对向日葵修复铜污染土壤效率的影响。【结果】1）不同螯合剂用量对铜污染土壤的浸提效果显著不同，根据螯合剂浸提土壤铜的高含量低毒性效应，选取EDTA 3 mmo1/kg土和DTPA 5 mmo1/kg土作为螯合剂的施加剂量。2）施入螯合剂后，CO2浓度升高一定程度上缓解了向日葵的失绿、失水，增加了食葵3号和阿尔泰2号的总生物量，但降低了食葵4号和阿尔泰1号的总生物量。3）在相同CO2浓度下，加入螯合剂后明显提高土壤PH值，且DTPA处理的增幅明显高于EDTA处理。CO2浓度升高处理虽对土壤PH值有影响，但CO2施肥与不施肥处理间五个品种的土壤PH值无显著差异。4）试验选用的5个品种中，食葵4号、阿尔泰1号在CO2浓度升高后，向日葵地上部蓄铜量明显降低；食葵3号、油生引2号在CO2浓度升高后，向日葵地上部蓄铜量略有升高；阿尔泰2号在二氧化碳浓度升高后，向日葵地上部蓄铜量明显升高。CO2与DTPA 5 mmo1/kg土联合施用，5个品种向日葵茎叶内铜含量较对照增加239%646%；铜蓄积量较对照增加230%362%。二氧化碳与EDTA 3 mmo1/kg 联合施用时，EDTA的活化作用未达到最佳效果，对5个品种向日葵茎、叶内铜含量的影响不一致。【结论】CO2浓度升高一定程度上可以增强向日葵的抗性。在100 mg/kg铜污染土壤上，阿尔泰2号对二氧化碳浓度升高的反应最敏感，同时二氧化碳与螯合剂联合施用时，螯合剂可能是影响土壤PH值变化的主要因子。在铜污染水平为100 mg/kg的土壤上，与EDTA施用量为3 mmo1/kg土相比，5 mmo1/kg土的DTPA与CO2联合施用的修复效果更好。
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