镉胁迫对八角金盘生长及生理特性的影响

Effects of Cadmium Stress on Growth and Physiological Characteristics of Fatsia japonica

本研究通过对常用绿化植物八角金盘一年生实生苗进行不同浓度CdCl_(2)溶液[CK(0μmol/L Cd^(2+)),Cd1(20μmol/L Cd^(2+)),Cd2(40μmol/L Cd^(2+)),Cd3(80μmol/L Cd^(2+))和Cd4(120μmol/L Cd^(2+))]处理,探究镉胁迫对八角金盘生长及生理特性的影响。结果显示,20μmol/L镉胁迫对八角金盘植株影响较小,表现为株高、叶片数、叶面积、最大光化学效率(F_(v)/F_(m))、实际光化学效率(Y(Ⅱ))等变化不显著;40、80μmol/L镉胁迫处理下,其生长指标下降,丙二醛(MDA)含量上升,抗氧化酶活性和可溶性蛋白含量上升,说明此浓度下植株可通过自身抗氧化机制等来适应镉胁迫;120μmol/L镉胁迫下,植株株高、叶面积显著降低,叶绿素含量、F_(v)/F_(m)、Y(Ⅱ)、可溶性蛋白含量均显著下降至最低,MDA含量累积较高,说明在高浓度镉胁迫下植株生长严重受抑,且膜脂过氧化严重。本研究结果可为八角金盘在镉污染土壤条件下的推广种植提供理论参考。

In this study,in ord er to i nvestigate the effect of cadmium stress on the growth and physiological characteristics of Fatsia japonica,we treated their seeding plants with different concentration of CdCl_(2)solution[CK(0μmol/L Cd^(2+)),Cd1(20μmol/L Cd^(2+)),Cd2(40μmol/L Cd^(2+)),Cd3(80μmol/L Cd^(2+))and Cd4(120μmol/L Cd^(2+))]under cadmium stress.The results showed that cadmium stress with 20μmol/L Cd^(2+)had little effect on F.japonica growth and physiological indexes,and showed no significant changes in plant height,number of leaves,the leaf areas,the maximum photochemical efficiency of PSII(F_(v)/F_(m))and actual photochemical efficiency(Y(Ⅱ)).Under the 40 and 80μmol/L cadmium stresses,the growth index decreased significantly,while the malondialdehyde(MDA)content,antioxidant enzyme activities and soluble protein content increased,indicating that the plants could improve its own antioxidant mechanism to adaption the cadmium stress.Under the stress of 120μmol/L cadmium,the plant height,leaf area,the chlorophyll contents,F_(v)/F_(m),Y(Ⅱ)and soluble protein content were significantly reduced to the lowest level,while MDA content was highly accumulated,which suggested that the growth of F.japonica plant was seriously inhibited and membrane lipid peroxidation was serious under the high concentration of cadmium stress.It provides theoretical reference for the popularization of F.japonica planting in cadmium contaminated soil.