Cr^(6+)对人工湿地薏苡光合特性和微量元素吸收的影响  

Effects of Cr^(6+)on photosynthetic characteristics and trace element absorption of Coix lacryma-jobi in constructed wetland

作　　者：柳心怡 农宇 黄建祥[1] 李素丽[1] 李良香 程夕冉[1] 王学礼[1] 李正文[1] 李志刚[1] LIU Xinyi;NONG Yu;HUANG Jianxiang;LI Suli;LI Liangxiang;CHENG Xiran;WANG Xueli;LI Zhengwen;LI Zhigang(College of Agricultural,Guangxi University,Nanning 530003,China)

机构地区：[1]广西大学农学院,南宁530005

出　　处：《广西植物》2022年第11期1959-1970,共12页Guihaia

基　　金：国家自然科学基金(21167002,41867023);广西自然科学基金(2018GXNSFAA281214)。

摘　　要：为深入了解Cr^(6+)胁迫对人工湿地植物薏苡光合特性和微量元素吸收的影响,该文通过构筑微型垂直流薏苡(Coix lacryma-jobi)人工湿地,采用1/2 Hoagland’s营养液配制的含0、5、20、40 mg·L^(-1) Cr^(6+)废水为灌溉用水,研究铬胁迫对人工湿地植物生长、光合特性、抗氧化酶活性和微量元素吸收等的影响。结果表明:(1)低浓度(5 mg·L^(-1))Cr^(6+)对薏苡的株高、茎粗和分蘖影响不显著,高浓度(20、40 mg·L^(-1))Cr^(6+)则显著抑制薏苡的生长。(2)低浓度Cr^(6+)处理下,薏苡叶片净光合速率(P_(n))、气孔导度(G_(s))和蒸腾速率(T_(r))有不同程度的提高,提高幅度分别为6.8%~54.8%、13.0%~40.3%和9.1%~36.4%。高浓度Cr^(6+)处理下,叶片P_(n)、G_(s)、T_(r)等指标显著下降,但叶片胞间CO_(2)浓度(C_(i))则显著提高。(3)薏苡叶片超氧化物歧化酶(SOD)和过氧化物酶(POD)活性均随着处理时间的延长而提高;低浓度Cr^(6+)处理下,薏苡叶片SOD活性与对照差异不大,高浓度Cr^(6+)处理下,SOD活性受到显著抑制。薏苡叶片POD活性和丙二醛(MDA)含量均随Cr^(6+)处理浓度的提高而提高。(4)高浓度Cr^(6+)处理显著抑制根系、茎、叶对Cu、Fe、Mn和Zn的吸收。(5)5、20 mg·L^(-1) Cr^(6+)处理下,人工湿地对Cr^(6+)去除率最高可达99%,40 mg·L^(-1) Cr^(6+)处理下最高则为86%。综上认为,Cr^(6+)胁迫导致Fe、Mn、Zn和Cu等元素吸收量显著下降,光合受阻,抗氧化系统受损,植物生长受到抑制,最终导致人工湿地处理含Cr^(6+)废水的能力下降。In order to understand the effects of Cr^(6+)stress on the photosynthetic characteristics and trace element absorption of Coix lacryma-jobi,we investigated the effects of Cr stress on the growth,photosynthetic characteristics,antioxidant enzyme activity and microelement absorption of C.lacryma-jobi by constructing a miniature vertical flow C.lacryma-jobi artificial wetland with 1/2 Hoagland’s nutrient solution containing 0,5,20,40 mg·L^(-1) Cr^(6+)wastewater as irrigation water.The results were as follows:(1)Low concentration(5 mg·L^(-1))of Cr^(6+)had no significant effects on plant height,stem thickness and tillering of C.lacryma-jobi,while high concentrations(20,40 mg·L^(-1))of Cr^(6+)significantly inhibited the growth of C.lacryma-jobi.(2)Net photosynthetic rate(P n),stomatal conductance(G s)and transpiration rate(T r)of C.lacryma-jobi leaves were increased to different degrees under low Cr^(6+)treatment,with the increases ranging from 6.8%to 54.8%,from 13.0%to 40.3%and from 9.1%to 36.4%,respectively.Under the high concentration of Cr^(6+)treatment,the P n,G s and T r of leaves decreased significantly,but the intercellular CO_(2) concentration(C i)increased significantly.(3)Both superoxide dismutase(SOD)and peroxidase(POD)activities of C.lacryma-jobi leaves increased with increasing treatment time;SOD activity of C.lacryma-jobi leaves did not significantly differ from the control under low Cr^(6+)treatment,and was significantly inhibited under high Cr^(6+)treatment.The POD activity and malondialdehyde(MDA)content of C.lacryma-jobi leaves increased with the increase of Cr^(6+)treatment concentration.(4)The absorption of Cu,Fe,Mn and Zn by roots,stems and leaves was significantly inhibited by high concentration of Cr^(6+)treatment.(5)The removal rate of Cr^(6+)by the artificial wetland was up to 99%under 5 and 20 mg·L^(-1) Cr^(6+)treatments,and 86%under 40 mg·L^(-1) Cr^(6+)treatment.All the results indicate that Cr^(6+)stress leads to a significant decrease in the absorption of Fe,Mn,Zn and Cu,hinders pho

关 键 词：铬 人工湿地 光合作用 微量元素 抗氧化酶 

分 类 号：Q948[生物学—植物学]