铬胁迫对美人蕉生理生态特性与铬积累的影响

摘要

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(Pn)、气孔导度(Gs)最高,而低浓度(小于40 mg/L)胁迫下蒸腾速率(Tr)、胞间CO2含量(Ci)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 phytoremedi-ation 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 ani-on 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, Pn and Gs was the highest values . Under lower Cr(VI) concentration (less than 40 mg/L) stress, Tr and Ci had no significant difference.Therefore, Canna indica had a good adaptability and pollution resistance ability to Cr (VI) stress, which was an excellent con-structed wetland plant in the treatments of Cr wastewaters .