Ceulemans R, VAN Praet L, Jiang X N
Department of Biology, University of Antwerpen (UIA), Universiteitsplein 1, Wilrijk B-2610, Belgium.
On leave from the Experimental Centre of Forest Biology, Beijing Forestry University, Beijing 100083, PR. China.
New Phytol. 1995 Sep;131(1):99-107. doi: 10.1111/j.1469-8137.1995.tb03059.x.
The effects of CO , enrichment and leaf position on stomatal characteristics (stomatal density, stomatal index and stomatal pore length) and epidermal cell density were examined for two different Populus clones, Beaupre and Robusta, grown from cuttings in open-top chambers under ambient and elevated atmospheric CO conditions. Both clones had amphistomatous leaves, and stomatal density was significantly larger on the abaxial leaf surface than on the adaxial. Significant interactions between CO enrichment, leaf position and clone were observed for most stomatal and epidermal characteristics. A significant reduction of the number of stomata mm under elevated CO was observed in expanding leaves near the upper portion of the plant for both leaf surface sides and in both clones. For the abaxial leaf side only, this reduction under elevated CO , was accompanied by a similar reduction of the stomatal index in both clones. In mature leaves on the middle and lower portion of the plants, there was no significant effect of the CO treatment on stomatal density. In young, expanding leaves near the upper part of the plant there were significant interactions between the CO treatment and leaf surface side for epidermal cell density. The latter increased under elevated CO at the abaxial leaf surface, but decreased at the adaxial surface on the upper part of the plant. Total epidermal cell numbers of mature, fully expanded leaves increased under elevated CO , in both clones. The observation that interactions with leaf age and/or leaf position significantly confound the CO , treatment effect on stomatal and epidermal cell densities, might contribute to the elucidation of the problem of the phenomenon of stomatal density reduction under elevated atmospheric CO .
在开放式气室中，于环境大气CO₂浓度和升高的大气CO₂浓度条件下，以插条繁殖的两个不同杨树无性系（博普雷和罗布斯塔）为材料，研究了CO₂浓度升高和叶位对气孔特征（气孔密度、气孔指数和气孔孔径长度）以及表皮细胞密度的影响。两个无性系的叶片均为双面气孔叶，且气孔密度在下表面显著大于上表面。对于大多数气孔和表皮特征，观察到CO₂浓度升高、叶位和无性系之间存在显著的交互作用。在植株上部附近正在展开的叶片中，两个无性系的上下表面在CO₂浓度升高时，气孔数量均显著减少。仅对于下表面而言，在CO₂浓度升高时，两个无性系的气孔指数也有类似程度的降低。在植株中下部的成熟叶片中，CO₂处理对气孔密度没有显著影响。在植株上部附近幼嫩的、正在展开的叶片中，CO₂处理与叶表面对于表皮细胞密度存在显著的交互作用。在CO₂浓度升高时，植株上部叶片下表面的表皮细胞密度增加，而上表面的表皮细胞密度降低。在两个无性系中，成熟、完全展开叶片的表皮细胞总数在CO₂浓度升高时均增加。与叶龄和/或叶位的交互作用显著混淆了CO₂处理对气孔和表皮细胞密度的影响，这一观察结果可能有助于阐明大气CO₂浓度升高时气孔密度降低现象的问题。
