中文摘要：

利用开顶式气室（OTC）研究了O3胁迫（空气0，浓度加118μg·m^-3）、干旱胁迫（土壤水分保持在田间持水量的40％-50％）以及O3与干旱复合胁迫（空气0，浓度加118μg·m^-3和土壤水分保持在田间持水量的40％～50％）对元宝枫（Acer truncatum Bunge．）叶片气孔特征的影响。结果表明：O3胁迫41d时气孔密度变化不明显，62和110d时显著增加（P〈0．05）；干旱胁迫和复合胁迫下气孔密度增加显著（P〈0．05）；O3、干旱及复合胁迫处理110d气孔面积、周长、长度和宽度明显减小（P〈0．05），气孔指数明显增加（P〈0．05）；各胁迫气孔开度均明显减小（P〈0．05），O3和干旱对气孔开度影响存在协同作用，干旱减小了O3胁迫下的气孔开度。O3和干旱胁迫下气孔特征响应不同表明影响气孔的机制不同，O3对气孔影响具有累积效应，干旱可限制O3摄入量从而减小了O3对植物的伤害。

英文摘要：

An open-top chambers （OTCs） experiment was carried on the combined effects of ozone and drought on leaf stomata of Acer mmcatum Bunge. Four treatments were designed ： con- trol （ambient air without drought stress）, drought （ambient air with 40-50% of soil water-hold- ing capacity） , enhanced ozone （ambient air with additional 118 μg·m^-3 ozone without drought stress）, and enhanced ozone and drought （ambient air with additional 118 μg·m^-3 ozone and 40-50% of soil water-holding capacity）. 41 days after treatment, the stomatal density did not change significantly under ozone exposure, but increased significantly under drought stress and combined stress （P〈0.05）. 41 and 62 days after treatment with ozone and drought stresses, there were no significant differences in stomatal area, length and width among treatments （P〉 0.05）, while 110 days after treatment with ozone and drought, the stomatal area, length and width were smaller than those of the control （ P〈0.05 ）. Compared with the control, stomatal in- dex increased significantly 110 days after treatment by ozone and drought （ P〈0.05 ）. The stoma- tal opening degree reduced significantly when A. truncatum was exposed to enhanced ozone and drought （P〈0.05）. These results suggested that accumulating effects were reflected on stomatal characteristics of A. truncatum under ozone stresses. Ozone and drought stresses influenced the stomatal characteristics interactively. The synergistic effect of ozone and drought stresses was evi- denced on the stomatal aperture. It was suggested that drought could protect plants against ozone- induced damage by causing the closure of stomata and preventing the entry of ozone into the leaves.