| 摘要: |
| 将尖叶杜英（Elaeocarpus apiculatus）、米老排（Mytilaria laosensis）和藜蒴（Castanopsis fissa）幼苗置于开顶气室进行人工臭氧熏气和干旱处理，测定其0,15,30 d时的净光合速率（Pn）、气孔导度（Gs）、胞间CO2浓度(Ci)、蒸腾速率(Tr），并计算气孔限制值(Ls)。结果显示：(1)臭氧胁迫、干旱胁迫及臭氧和干旱交叉胁迫的影响下，3种幼苗的Pn、Gs和Tr随处理时间的延长均呈下降趋势，Ci上升或下降后上升，Ls下降或上升后下降；（2）臭氧胁迫期间，尖叶杜英的Pn下降由非气孔限制引起，而米老排和藜蒴的Pn下降由气孔限制转为非气孔限制所致；干旱胁迫期间，尖叶杜英和米老排的Pn下降由气孔限制转为非气孔限制所致，而藜蒴的Pn下降由非气孔限制引起；在臭氧与干旱交叉胁迫下，3种幼苗的Pn下降均由非气孔限制所致；（3）主成分分析表明，幼苗抗干旱胁迫及臭氧与干旱交叉胁迫的能力为米老排>尖叶杜英>藜蒴，幼苗抗臭氧胁迫的能力为米老排>藜蒴>尖叶杜英。 |
| 关键词: 臭氧胁迫 干旱胁迫 幼苗 气体交换参数 |
| DOI： |
| 投稿时间：2014-03-11修订日期：2014-03-26 |
| 基金项目:广东省林业科技创新专项资金项目“资源互补机制在林分改造上的应用研究与示范”（2010KJCX013-01） |
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| Effects of Ozone and Drought Stress on Photosynthetic Physiology of Three Species Seedlings in South China |
| Li Qiujing,,Xue Li |
| (College of Forestry, South China Agricultural University) |
| Abstract: |
| In this study, Elaeocarpus apiculatus, Mytilaria laosensis, and Castanopsis fissa seedlings were placed in open top chambers for artificial ozone fumigation and drought treatments. Net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci), and transpiration rate (Tr) were determined 0, 15, and 30 d after treatment, and the corresponding stomatal limitation (Ls) was calculated. With increasing ozone, drought, or ozonedrought intercross stress duration, Pn, Gs, and Tr of the three species seedlings tended to decrease, Ci increased or alternatively decreased and then increased, and Ls decreased or alternatively increased and then decreased. Decreases in Pn during the ozone stress period could be attributed to nonstomatal limitations in E. apiculatus, and stomatal and non stomatal limitations in M. laosensis and C. fissa. Observed decreases in Pn under drought stress were the result of stomatal and non stomatal limitations in E. apiculatus and M. laosensis, and non stomatal limitations in C. fissa. During the intercross stress period, decreases in Pn in all three species seedlings were due to non stomatal limitations. Based on principal component analysis, the three species seedlings were ordered with respect to drought resistance and intercross stress resistance as M. laosensis > E. apiculatus > C. fissa, whereas their resistance to ozone stress was M. laosensis > C. fissa>E. apiculatus. |
| Key words: ozone stress drought stress seedling gas exchange parameters |
