铬胁迫对美人蕉生理生态特性与铬积累的影响

Response of Physiological and Ecological Characteristics of Canna indica under Cr(Ⅵ) Stress

选取大小一致的美人蕉(Canna indica)作为研究试材,在小型模拟人工湿地系统中,研究含不同浓度(0、5、10、20、40、60 mg/L)铬(VI)胁迫下美人蕉的生理生态响应,为处理含铬(VI)废水的植物修复材料提供科学依据。结果表明,不同浓度铬(VI)胁迫下,美人蕉叶绿素、丙二醛(MDA)、还原型谷光甘肽(GSH)含量呈现出不同程度的变化趋势;其含量先升高后降低,但超氧阴离子变化趋势相反;同时脯氨酸(Pro含量)在不同浓度胁迫下无显著差异。超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)和苯丙氨酸解氨酶(PAL)活性随铬胁迫浓度的增加呈现先升后降的趋势。铬胁迫浓度为20 mg/L时净光合速率(P_n)、气孔导度(G_s)最高,而低浓度(小于40 mg/L)胁迫下蒸腾速率(T_r)、胞间CO_2含量(C_i)无显著差异。综上,铬胁迫下美人蕉对其生理生态特性做出相应的调整,表现较强的适应力和耐污力,可作为处理含铬废水的湿地植物备选物种之一。

The selection of the same size of Canna indica was studied in a small Constructed wetland system,and the physiological and ecological characteristics of Canna indica were studied under different concentrations of Cr（Ⅵ）（0,5,10,20,40,60 mg/L） stress,which can provide scientific basis for the selection of phytoremediation materials to treat chromium（Ⅵ） wastewaters.The results showed that the contents of Chlorophyll,MDA and GSH of Canna indica under Cr（Ⅵ） stress increased firstly and then decreased,but the content of superoxide anion is opposite and the content of Pro had no significant difference.The contents of SOD,CAT,and POD were also increased firstly and then decreased.When Cr（Ⅵ） concentration was 20 mg/L,Pnand Gswas the highest values.Under lower Cr（Ⅵ） concentration（less than 40 mg/L） stress,Trand Cihad no significant difference.Therefore,Canna indica had a good adaptability and pollution resistance ability to Cr（Ⅵ） stress,which was an excellent constructed wetland plant in the treatments of Cr wastewaters.