模拟酸雨对乐东拟单性木兰幼苗部分生理指标的影响  

Effects of simulated acid rain on some physiological indices of Parakmeria lotungensis seedlings

作　　者：李志国[1] 翁忙玲[1] 姜武[1] 姜卫兵[1] 

机构地区：[1]南京农业大学园艺学院,南京210095

出　　处：《生态学杂志》2007年第1期31-34,共4页Chinese Journal of Ecology

基　　金：江苏省级综合性农业科技示范园资助项目(苏农计(2003)50号)

摘　　要：采用盆栽法,研究了不同pH值的模拟酸雨胁迫对乐东拟单性木兰(Paramecialo-tungensis)叶片膜损伤、抗氧化酶活性、叶绿素(Chl)含量以及气体交换参数等的变化。结果表明:在模拟酸雨胁迫下,幼苗叶片膜透性和丙二醛(MDA)含量显著增加,且两者呈现显著正相关;过氧化氢酶(CAT)活性逐渐下降,超氧化物歧化酶(SOD)和过氧化物(POD)活性逐渐或急剧上升;Chl含量明显下降;净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、水分利用效率(WUE)和气孔限制值(Ls)等指标均呈下降趋势,而胞间CO2浓度(Ci)却表现为上升趋势。表明酸雨诱导了活性氧生成,使抗氧化酶系统失调,造成活性氧产生和清除之间的不平衡,从而加速膜脂过氧化作用,破坏膜透性,降解叶绿素,导致光合作用下降。With pot experiment, this paper studied the effects of simulated acid rain on the membrane injury, antioxidant enzyme activities, chlorophyll （Chl） content, and gas exchange of Paramecia lotungensis seedlings leaves. The results showed that under simulated acid rain stress, the membrane permeability and malondialdehyde （MDA） content of P. lotungensis leaves increased significantly, and there was a significant correlation between them. The catalase （CAT） activity decreased gradually, while superoxide dismutase （SOD） and peroxidase （POD） activities in- creased gradually or greatly. Chl content had an obvious decrease, and net photosynthetic rate （Pn）, stomatal conductance （Ga）, transpiration rate （Tt）, water use efficiency （ WUE ）, and stomatal limitation value （La） all had a decreasing trend. The intercellular CO2 concentration （Ci） tended to increase. All of these suggested that simulated acid rain induced the production of activated oxygen （ O2 T ）, resulting in the maladjustment of antioxidant enzyme system and the imbalance between O2 T production and elimination, which in turn accelerated lipid peroxidation, damaged membrane permeability, disorganized chlorophyll structure, and decreased photosynthetic rate.

关 键 词：模拟酸雨 乐东拟单性木兰 光合作用 膜损伤 

分 类 号：X173[环境科学与工程—环境科学]