镉胁迫对黄秋英生理及富集特性的影响

Effects of Cadmium Stress on Physiological and Enrichment Characteristics of Cosmos sulphureus

为给土壤镉(Cd)污染地区提供具有景观修复性的植物修复材料,本试验采用盆栽方法,研究不同质量浓度镉(0、0.3、3、30、60、120、180 mg/kg)对黄秋英(Cosmos sulphureus)植株生理及富集特性的影响。结果表明:胁迫15 d时,随着镉浓度增加,黄秋英叶片可溶性蛋白、叶绿素a、叶绿素b、类胡萝卜素含量和SOD活性均呈先升后降趋势,MDA含量逐渐下降,POD活性先降后升;ETR、qP、Tr在镉浓度0.3 mg/kg时达到最高,Pn与Gs在镉浓度3 mg/kg时达到最高,NPQ在镉浓度30 mg/kg时降到最低,Fv/Fm在镉浓度60 mg/kg时达到最高,Fo在镉浓度180 mg/kg时降到最低。胁迫30 d时,其可溶性蛋白含量、SOD活性先升后降,MDA含量先升后降再升高,POD活性先降后升再下降,叶绿素a、叶绿素b、类胡萝卜素含量先降后升;镉浓度0.3 mg/kg时Fv/Fm达到最高,镉浓度3 mg/kg时NPQ达到最高,而Tr、Pn、Gs降到最低,镉浓度30 mg/kg时qP达到最高、Fv/Fm降到最低,镉浓度60 mg/kg时Pn、Gs达到最高,而Fo、NPQ降到最低,镉浓度120 mg/kg时Ci降到最低,镉浓度180 mg/kg时Tr、ETR达到最高。镉浓度<180 mg/kg时,黄秋英各器官镉含量表现为茎>根>叶;镉浓度≥180 mg/kg时为根>茎>叶。镉浓度≥120 mg/kg时黄秋英根、茎及地上部镉含量均超过镉超富集植物的临界值。综上看出,黄秋英在高浓度镉胁迫下具有较高的耐受力,同时具备较强的镉富集能力,可作为具有景观修复性的植物修复材料。

In order to provide phytoremediation materials with landscape restorative properties for areas contaminated by soil cadmium(Cd),the pot experiment was conducted to study the effects of different mass concentrations of Cd(0,0.3,3,30,60,120,180 mg/kg)on physiological and enrichment characteristics of Cosmos sulphureus plants.The results were as follows.At 15 days of stress,with the increase of cadmium concentration,the soluble protein,chlorophyll a,chlorophyll b and carotenoid contents and SOD activity in leaves of C.sulphureus showed the tendency of firstly increasing and then decreasing,the MDA content de-creased gradually,and the POD activity decreased first and then increased;ETR,qP and Tr reached the highest values at 0.3 mg/kg of cadmium,Pn and Gs reached the highest values at 3 mg/kg of cadmium,NPQ reached the lowest value at 30 mg/kg of cadmium,Fv/Fm reached the highest value at 60 mg/kg of cadmium,and Fo reached the lowest value at 180 mg/kg of cadmium.At 30 days of stress,soluble protein content and SOD activity increased first then decreased,MDA content increased first then decreased and then increased,and POD activity decreased first then increased and then decreased;chlorophyll a,chlorophyll b and carote-noid contents decreased first and then increased;Fv/Fm reached the highest value at 0.3 mg/kg of cadmium,NPQ reached the highest value while Tr,Pn and Gs dropped to the lowest values at 3 mg/kg of cadmium;qP reached the highest level and Fv/Fm reached the lowest level at 30 mg/kg of cadmium;Pn and Gs reached the highest values but Fo and NPQ dropped to the lowest values at 60 mg/kg of cadmium;Ci decreased to the lowest value at 120 mg/kg of cadmium,and Tr and ETR were the highest at 180 mg/kg of cadmium.When Cd concentration was<180 mg/kg,the Cd content in the organs showed stems>roots>leaves,and showed roots>stems>leaves when Cd concentration was≥180 mg/kg.When the cadmium concentration was≥120 mg/kg,the cadmium content in roots,stems and aboveground parts of C.sulphureus exceeded the critical val-ue of cadmium super-enriched plants.In conclusion,C.sulphureus had excellent tolerance to high concentra-tion cadmium stress and strong cadmium enrichment ability,which could be used as a phytoremediation mate-rial with landscape restoration.