| 摘要: |
| 【目的】探求欧洲云杉对干旱胁迫的适应机制，为选择耐旱性较强的欧洲云杉提供科学依据。【方法】通过盆栽试验，对欧洲云杉4个无性系(pab08mg003，pab08mg004，pab08mg005，pab08mg006)在不同干旱胁迫下的叶水势、耗水量、耗水速率和水分利用效率进行研究。【结果】(1)欧洲云杉不同无性系在整个干旱胁迫过程中叶水势均呈下降趋势。正常水分条件下各无性系叶片水势差异不明显(P=0.198)；在重度干旱胁迫下，叶水势由高到低为pab08mg003(－1.96 MPa)＞pab08mg005(－2.05 MPa)＞pab08mg004(－2.14 MPa)＞pab08mg006(－2.25 MPa)，无性系pab08mg003和pab08mg005在重度干旱下仍能保持较高的水势，表明其抵御干旱的能力较强。(2)不同干旱胁迫下苗木的白天耗水量占全天耗水量的85.24%～93.85%。(3)欧洲云杉无性系耗水速率日变化趋势均为明显的双峰曲线，在受到胁迫时，第1个峰值的出现时间由正常水分条件下的10:00-12:00提前到08:00-10:00，第2个峰值出现时间保持在14:00-16:00不变。干旱胁迫后耗水速率日变化值和降幅均为pab08mg003＞pab08mg005＞pab08mg006＞pab08mg004，说明无性系pab08mg003和pab08mg005对干旱胁迫的反应较为敏感，有较强的干旱适应能力。(4)轻度和中度干旱胁迫下，各无性系水分利用效率(WUE)均有所上升，都能通过提高WUE来应对干旱胁迫；重度干旱胁迫下，pab08mg005的瞬时WUE维持在较高水平((3.72±0.13) mmol/mol)，pab08mg003和pab08mg006次之，pab08mg004则下降为0。【结论】各无性系适应干旱的能力为pab08mg005＞pab08mg003＞pab08mg006＞pab08mg004。 |
| 关键词: 欧洲云杉 干旱胁迫 叶水势 耗水量 耗水速率 水分利用效率 |
| DOI： |
| 分类号: |
| 基金项目:国家“十二五”科技支撑计划项目（2012BAD01B01） |
|
| Effects of drought stress on water physiological characteristics of Picea abies |
|
LIN Wen,HE Qian,SU Yan,et al
|
| Abstract: |
| 【Objective】This study aimed to reveal the adaption mechanism of Picea abies to drought stress and provide a scientific basis for selection of species with strong drought tolerance.【Method】Seedlings of four Picea abies clones (pab08mg003,pab08mg004,pab08mg005,and pab08mg006) were planted in pots to study the changes of leaf water potential,drought stress,water consumption,water consumption rate and water use efficiency under different drought stresses.【Result】Water potentials of four Picea abies clones decreased during the entire process of drought stress.There was no obvious difference on leaf water potential among all clones under normal water condition (P=0.198).With severe drought stress,the leaf water potentials were in a decreasing order of pab08mg003 (－1.96 MPa)＞pab08mg005 (－2.05 MPa)＞pab08mg004 (－2.14 MPa)＞pab08mg006 (－2.25 MPa).Clones of pab08mg003 and pab08mg005 remained high water potentials,indicating that they had strong resistance to drought.The water consumption in day time accounted for 85.24%－93.85%.Daily variation of Picea abies was a double-peak curve.With drought stress,the first peak advanced to 8:00-10:00 from 10:00-12:00,and the second peak remained at 14:00-16:00.The daily variation value and the decrease of water consumption rate were all in a decreasing order of pab08mg003＞pab08mg005＞pab08mg006＞pab08mg004,indicating that clones of pab08mg003 and pab08mg005 were more sensitive to environment change and had strong adaptability to drought.Water use efficiencies of all clones increased when the drought stresses were light and moderate.When the drought stress was serious,only pab08mg005 maintained high level water use efficiency at ((3.72±0.13) mmol/mol),pab08mg003 and pab08mg006 had poor water use efficiencies,while water use efficiency of pab08mg004 reduced to zero.【Conclusion】The resistance abilities against drought stress of Picea abies clones were in a decreasing order of pab08mg005＞pab08mg003＞pab08mg006＞pab08mg004. |
| Key words: Picea abies leaf water potential drought stress water consumption water consumption rate water use efficiency |
