Department of Forestry, University of Wisconsin, Madison, Wisconsin 53706.
Plant Physiol. 1979 Jul;64(1):112-4. doi: 10.1104/pp.64.1.112.
Responses of stomata of clones of Populus candicans Ait. x P. berolinensis Dipp. and Populus deltoides Bartr. x P. caudina (Ten.) Bugala to two levels of light intensity and vapor pressure deficit were studied in controlled environments. Significant stomatal responses to light and vapor pressure deficit were observed. Interactive effects of low light intensity and high vapor pressure deficit elicited greater stomatal closure than was obtained under low light or high vapor pressure deficit alone, indicating adaptation for increased water use efficiency under conditions unfavorable for photosynthesis relative to transpiration. Adaxial stomata of both clones were more sensitive than abaxial stomata to changing vapor pressure deficit and light intensity. Stomatal response to vapor pressure deficit appeared to be independent of bulk leaf water status. Stomata of P. candicans x P. berolinensis were more sensitive than stomata of P. deltoides x P. caudina to a change in vapor pressure deficit and less sensitive to a change in light intensity. The sensitivity of stomata of P. candicans x P. berolinensis to vapor pressure deficit may be related to drought resistance in its parentage (P. berolinensis).
在受控环境中研究了美洲黑杨×欧美杨杂种和银腺杨×毛白杨无性系叶片气孔对两种光强和水汽压亏缺水平的响应。观察到气孔对光和水汽压亏缺有显著的响应。低光强和高气 汽压亏缺的交互作用引起的气孔关闭程度大于单独处于低光强或高气 汽压亏缺条件下的关闭程度，表明与蒸腾相比，在不利于光合作用的条件下，适应于提高水分利用效率。两个无性系的叶片上表皮气孔比下表皮气孔对水汽压亏缺和光强变化更为敏感。气孔对水汽压亏缺的响应似乎与叶片整体水分状况无关。美洲黑杨×欧美杨杂种的气孔对水汽压亏缺的敏感性高于银腺杨×毛白杨的气孔，而对光强变化的敏感性较低。美洲黑杨×欧美杨杂种气孔对水汽压亏缺的敏感性可能与其亲本（欧美杨）的抗旱性有关。
