模拟氮沉降对夏蜡梅幼苗生理生态特性的影响  

Effects of simulated nitrogen deposition on the eco-physiological characteristics of Sinocalycanthus chinensis seedlings

作　　者：彭礼琼[1,2,3] 金则新[2,3] 王强[2,4] 

机构地区：[1]北京林业大学自然保护区学院,北京100083 [2]台州学院生态研究所,浙江台州318000 [3]浙江省植物进化生态学与保护重点实验室,浙江台州318000 [4]上海师范大学生命与环境科学学院,上海200030

出　　处：《生态学杂志》2014年第4期989-995,共7页Chinese Journal of 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

摘　　要：用氮浓度分别为2(低氮)、8(中氮)、32 g N·m-2·a-1(高氮)的NH4NO3溶液,喷淋盆栽夏蜡梅幼苗,以0 g N·m-2·a-1为对照(CK),1年后,比较其光合作用、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,探讨氮沉降对夏蜡梅幼苗生理生态特性的影响。结果表明:3种氮处理下,夏蜡梅幼苗叶片的日均净光合速率(Pn)和最大净光合速率(Pnmax)比对照分别增加了14.7%、54.5%、26.4%和8.3%、66.1%、30.9%,中氮处理下的日均Pn、Pnmax值最高。不同氮浓度处理后夏蜡梅幼苗叶片的日均气孔导度均高于CK,以中氮处理最高;而日均胞间CO2浓度均低于CK,以中氮处理最低。光补偿点、暗呼吸速率均为中氮>高氮>低氮>CK,差异极显著;而光饱点为中氮>低氮>CK>高氮,差异极显著;表观量子效率为中氮>低氮>CK,差异极显著,高氮与CK差异不显著。不同氮浓度处理的相对叶绿素含量均明显高于CK,以中氮处理最高。PSⅡ原初光能转化效率(Fv/Fm)、PSⅡ潜在活性(Fv/Fo)均为中氮>低氮>CK>高氮,差异极显著。不同氮处理的夏蜡梅幼苗叶片超氧化物歧化酶活性均高于CK,差异极显著,3种氮处理之间以高氮处理最高;过氧化物酶活性、丙二醛含量也以高氮处理最高,中氮次之,高氮、中氮处理与CK差异极显著,低氮处理与对照差异显著。不同氮处理的质膜离子渗漏为高氮>中氮>低氮>CK,差异极显著。本研究表明,不同浓度氮处理提高了夏蜡梅幼苗的光合作用能力,其中以中氮处理的效果最为明显,对其他生理指标也产生了一定的影响。We investigated the effects of simulated nitrogen deposition on the physiological and ecological characteristics of Sinocalycanthus chinensis seedlings by adding various amounts of NH4NO3 in a pot experiment. Three levels of NH4NO3 included： low-N （2 g N m-2·a-1）, medium-N （8 g N m-2·a-1）, and high-N （32 g N m-2·a-1）, with 0 g N m-2·a-1 as the control. After one year, we measured the photosynthetic characteristics, relative chlorophyll content, chlorophyll fluorescence parameters, membrane lipid peroxidation, and antioxidant enzyme activities in leaves of S. chinensis seedlings among the different treatments. The diurnal mean values of net photosynthetic rate at the low, medium, and high levels of N addition were 14.7%, 54.5%, and 26.4% higher than that of the control, respectively; the maximum net photosynthetic rates were 8.3%, 66.1%, and 30.9% higher than that of the control, respectively. The highest values for net photosynthetic rate and maximum net photosynthetic rate were recorded for the medium-N level. The daily mean stomatal conductance was higher in all N treatments than in the control, and the highest value was recorded for the medium-N level. However, the intercellular CO2 concentrations were lower in all N treatments than in the control; the lowest value was recorded in the medium-N treatment. The light compensation point and dark respiration rate among the four treatments were in the order of medium-N 〉 high-N 〉 low-N 〉 control, with highly significant differences among the treatments. In terms of the light saturation point, the treatments were ranked as follows： medium-N 〉 low-N 〉 control 〉 high-N, with highly significant differences among the treatments. The apparent quantum yield values were ranked as follows： medium-N 〉 low-N 〉 control; however, there was no significant difference between the high-N treatment and the control in the apparent quantum yield value. The relative chlorophyll contents in seedlings in the thre

关 键 词：夏蜡梅 光合生理 叶绿素荧光参数 膜脂过氧化 抗氧化酶活性 

分 类 号：S685.99[农业科学—观赏园艺]