NH_(4)^(+)和CO_(2)复合胁迫对水蕴草及其生长水体的影响  

Effects of NH_(4)^(+)and CO_(2)combined stress on Elodea densa and its growing water body

作　　者：常雅军[1] 王巍[1,2] 刘吉祥 李韵涵 孙林鹤 姚东瑞 CHANG Yajun;WANG Wei;LIU Jixiang;LI Yunhan;SUN Linhe;YAO Dongrui(Institute of Botany,Jiangsu Province and Chinese Academy of Sciences(Nanjing Botanical Garden,Mem.Sun Yat-Sen),Nanjing 210014,China;College of Ecology and Environment,Nanjing Forestry University,Nanjing 210037,China)

机构地区：[1]江苏省中国科学院植物研究所(南京中山植物园),江苏南京210014 [2]南京林业大学生态与环境学院,江苏南京210037

出　　处：《植物资源与环境学报》2025年第2期11-21,共11页Journal of Plant Resources and Environment

基　　金：江苏省省属公益类科研院所自主科研课题(BM2018021-6);江苏省“六大人才高峰”高层次人才项目(TD-JNHB-008)。

摘　　要：为了探究大气CO_(2)浓度升高背景下,水蕴草〔Elodea densa(Planch.)Casp.〕对水体NH_(4)^(+)胁迫的响应机制,设置2个NH_(4)^(+)质量浓度水平(1和6 mg·L^(-1))和3个CO_(2)流量水平(0.0、0.4和1.0 m^(3)·h^(-1),分别对应环境CO_(2)、低流量CO_(2)和高流量CO_(2)),对胁迫0、3、10和17 d时6个处理组的水体物理化学指标及水蕴草的生长量和生理生化指标〔包括叶绿素含量、抗氧化酶活性、丙二醛(MDA)含量和碳氮代谢关键酶活性〕进行了比较和双因素方差分析。结果显示:与胁迫0 d和NH_(4)^(+)单一胁迫处理组相比,胁迫3、10和17 d时,4个复合胁迫处理组水体的溶解氧含量和pH值显著(P<0.05)下降,而电导率、氧化还原电位、盐度、NH_(4)^(+)含量和HCO_(3)^(-)含量多显著升高,并且,CO_(2)流量对上述水体指标的影响以及NH_(4)^(+)质量浓度对水体NH_(4)^(+)含量的影响在0.001水平具有统计学意义,二者交互作用对水体NH_(4)^(+)含量的影响在0.05水平具有统计学意义。6个处理组的水蕴草生长量均为负值;在同一CO_(2)流量下,1和6 mg·L^(-1)NH_(4)^(+)处理组间的水蕴草生长量差异较小,而在同一NH_(4)^(+)质量浓度下,低流量和高流量CO_(2)处理组的水蕴草生长量显著低于环境CO_(2)处理组;并且,仅CO_(2)流量对水蕴草生长量的影响在0.001水平具有统计学意义。4个复合胁迫处理组水蕴草的叶绿素含量均随胁迫时间延长呈现先升高后降低的变化趋势;与环境CO_(2)处理组相比,整体而言,4个复合胁迫处理组水蕴草的超氧化物歧化酶和过氧化物酶活性在胁迫3 d时显著下降、在胁迫10和17 d时显著升高,过氧化氢酶活性在胁迫3、10、17 d时升高;在同一NH_(4)^(+)质量浓度下,高流量CO_(2)处理组水蕴草的MDA含量在胁迫10和17 d时显著低于低流量CO_(2)处理组。总体来看,在同一NH_(4)^(+)质量浓度下,低流量和高流量CO_(2)处理组水蕴草的谷氨酰胺合成酶(GS)、谷To explore the response mechanism of Elodea densa(Planch.)Casp.to NH_(4)^(+)stress of water body under the background of elevating atmospheric CO_(2)concentration,two NH_(4)^(+)mass concentration levels(1 and 6 mg·L^(-1))and three CO_(2)flow rate levels(0.0,0.4,and 1.0 m^(3)·h^(-1),corresponding to ambient CO_(2),low flow rate of CO_(2),and high flow rate of CO_(2),respectively)were set,the physical and chemical indexes of water body and growth increment and physiological and biochemical indexes〔including chlorophyll content,antioxidant enzyme activities,malonaldehyde(MDA)content,and activities of key enzymes in carbon and nitrogen metabolisms〕of E.densa in six treatment groups at 0,3,10,and 17 d of stress were compared and analyzed by using two-factor analysis of variance.The results show that,compared with 0 d of stress and NH_(4)^(+)single stress treatment group,at 3,10,and 17 d of stress,the dissolved oxygen content and pH value of the water body in the four combined stress treatment groups significantly(P<0.05)decrease,while the electric conductivity,oxidation-reduction potential,salinity,NH_(4)^(+)content,and HCO_(3)^(-)content mostly increase significantly,in addition,the effects of CO_(2)flow rate on the above indexes of water body and the effect of NH_(4)^(+)mass concentration on the NH_(4)^(+)content in the water body are statistically significant at the 0.001 level,and the effect of their interaction on the NH_(4)^(+)content in the water body is statistically significant at the 0.05 level.The growth increments of E.densa in the six treatment groups are all negative;under the same CO_(2)flow rate,the difference in growth increment of E.densa between 1 and 6 mg·L^(-1)NH_(4)^(+)treatment groups is relatively small,while under the same NH_(4)^(+)mass concentration,the growth increments of E.densa in the low and high CO_(2)flow rate treatment groups are both significantly lower than that in the ambient CO_(2)treatment group;moreover,only the effect of CO_(2)flow rate on the growth increment of E.dens

关 键 词：水蕴草 CO_(2) NH_(4)^(+) 复合胁迫 双因素方差分析 碳氮代谢 

分 类 号：Q945.78[生物学—植物学] X171.4[环境科学与工程—环境科学] X52