水分胁迫对常见绿化植物苗木光响应特性的影响  

Effects of Soil Water Stress on Light Response Characteristics of Seedlings of Landscape Plants

作　　者：王玉涛[1] 李吉跃[2] 刘平[1] 陈崇[3] 何春霞[3] 

机构地区：[1]沈阳农业大学,沈阳110161 [2]华南农业大学 [3]省部共建森林培育与保护教育部重点实验室(北京林业大学)

出　　处：《东北林业大学学报》2010年第7期42-45,60,共5页Journal of Northeast Forestry University

基　　金：国家自然科学基金(30671675);北京市科技计划资助项目(D0605001040191);沈阳农业大学青年教师科研基金(20081014,20092004)

摘　　要：采用盆栽试验研究正常供水(黎明前小枝水势ψ>-0.8MPa)和中度水分胁迫(-2.5MPa>ψ>-3.5MPa)条件下,3种生活型绿化植物苗木光响应特性。结果表明:3种生活型苗木光响应曲线均与非直角双曲线接近;在正常供水条件下,乔木、灌木和攀援植物苗木的最大光合速率(Pnmax)分别为10.44、11.17、16.40μmol·m-2·s-1,表观光合量子效率(AQ,Y)分别为0.066、0.045、0.037,暗呼吸速率(Rd)分别为0.56、1.47、1.51μmol·m-2·s-1,光补偿点(LC,P)分别为17、33、46μmol·m-2·s-1,光饱和点(LS,P)分别为336、358、612μmol·m-2·s-1;土壤水分胁迫能显著降低乔木、灌木和攀援植物苗木的Pnmax、AQ,Y,而对Rd无显著影响,LS,P和LC,P的变化因种类而不同。在土壤水分胁迫条件下,灌木表现出较高的光合活性,其Pnmax、AQ,Y和Rd值均比乔木和攀援植物高,表明灌木苗木对土壤水分的生态适应能力较强。An experiment was conducted to study the effects of soil water stress on the response of photosynthetic parameters to light intensities （0~2000 μmol·m-2·s-1） for the potted three and four-year-old seedlings of landscape plants （including trees,shrubs and lianas） under normal water supply （predawn water potential in branch ψ-0.8 MPa） and mild water stress （-3.5 MPaψ-2.5 MPa）. Results showed that light response curves of net photosynthetic rate in all the potted seedlings of the three life forms were nonrectangular hyperbola. Under normal water supply condition,the maximum net photosynthetic rates of seedlings of trees,shrubs and lianas were 10.44,11.17 and 16.40 μmol·m-2·s-1,apparent quantum yields were 0.066,0.045 and 0.037 μmol·μmol-1,dark respiration rates were 0.56,1.47 and 1.51 μmol·m-2·s-1,light compensation points were 17,33 and 46 μmol·m-2·s-1,and light saturation points were 336,358 and 612 μmol·m-2·s-1,respectively. Under soil drought stress,the maximum net photosynthetic rates and apparent quantum yields declined,dark respiration rates changed insignificantly,and light compensation points and light saturation points changed variously with different species. Shrub seedlings showed higher maximum net photosynthetic rate,apparent quantum yield and dark respiration rate compared with tree and shrub seedlings,indicating that shrubs have strong adaptability to soil water stress and light intensity.

关 键 词：水分胁迫 生活型 光响应曲线 水势 

分 类 号：S718.43[农业科学—林学] Q945.78[生物学—植物学]