摘要
2010年6月—2011年7月,采用盆栽模拟氮沉降试验,比较了不同氮浓度处理(CK0g·m-2·a-1、低氮2g·m-2·a-1、中氮8g·m-2·a-1、高氮32g·m-2·a-1)下乌药幼苗光合作用、相对叶绿素含量、叶绿素荧光参数、抗氧化酶活性及膜脂过氧化的差异,探讨氮沉降对乌药幼苗生理生态特性的影响.结果表明:经过1年的低氮、中氮和高氮处理,乌药幼苗叶片的日均净光合速率(Pn)和最大净光合速率(Pnmax)分别比对照增加了47.0%、117.8%、41.2%和82.6%、191.3%、152.2%;3种氮处理的乌药幼苗叶片日均Pn、Pnmax均以中氮处理最高.不同氮浓度处理后乌药幼苗叶片的日均胞间CO2浓度、日均气孔导度、光饱和点和表观量子效率均高于对照,暗呼吸速率以高氮处理最高.乌药幼苗叶片的相对叶绿素含量以中氮处理最高,其次是高氮处理,低氮处理与对照无显著差异.不同氮处理使乌药幼苗叶片的叶绿素荧光参数发生改变,PSⅡ原初光能转化效率、PSⅡ潜在活性均以高氮处理最低.3种氮处理的乌药幼苗叶片超氧化物歧化酶活性均高于对照,而过氧化物酶活性、丙二醛含量、膜透性均以高氮处理最高.氮沉降提高了乌药幼苗的光合能力,以中氮处理的效果最为明显,对其他生理指标也产生了不同程度的影响.
From June 2010 to July 2011,a pot experiment was conducted to explore the effects of nitrogen deposition on the leaf physiological and ecological characteristics of Lindera aggregate seedlings.Three levels of NH4NO3,i.e.,low-N （2 g·m-2·a-1）,medium-N （8 g·m-2·a-1）,and high-N （32 g·m-2·a-1）,were added to simulate nitrogen deposition,and the seedling leaf photosynthesis,relative chlorophyll content,chlorophyll fluorescence parameters,membrane lipid peroxidation,and antioxidant enzyme activities were determined.After one-year treatment,the daily mean values of the net photosynthetic rate （Pn） and the maximum net photosynthetic rate （Pn max） at low,medium and high levels of NH4NO3 addition were 47.0%,117.8% and 41.2%,and 82.6%,191.3% and 152.2% higher than those of the control （no NH4NO3 addition）,respectively,with the highest values at medium level of NH4NO3 addition.The intercellular CO2 concentration,daily mean stomatal conductance,light saturation point,and apparent quantum yield in the three treatments of NH4NO3 addition were all higher than those of the control,and the dark respiration rate was the highest in treatment high-N.The relative chlorophyll content was the highest in treatment medium-N,followed by in treatment high-N,and had no significant difference between treatment low-N and the control.The chlorophyll fluorescence parameters varied with the levels of NH4NO3 addition.The PSⅡ primary chemical efficiency （Fv/Fm） and PSⅡ potential activity （Fv/Fo） were the lowest in treatment high-N,the superoxide dismutase activity was higher in nitrogen addition treatments than in the control,and the peroxidase activity,malonydialdehyde content,and membrane permeability were the highest in treatment high-N.All the results suggested that nitrogen deposition enhanced the photosynthetic ability of L.aggregata seedlings,with the most obvious effects in treatment medium-N,and altered the other physiological traits of the seedlings to different degrees.
出处
《应用生态学报》
CAS
CSCD
北大核心
2012年第10期2766-2772,共7页
Chinese Journal of Applied Ecology
基金
国家自然科学基金项目(30870392)
浙江省自然科学基金项目(Y3080460)资助
关键词
模拟氮沉降
乌药
光合生理
叶绿素荧光参数
抗氧化酶活性
膜脂过氧化
simulated nitrogen deposition
Lindera aggregata
photosynthetic physiology
chlorophyll fluorescence parameter
antioxidant enzyme activity
membrane lipid peroxidation.
