Osonubi O, Davies W J
Department of Biological Sciences, University of Lancaster, LA1 4YQ, Lancaster, Lancs., U.K.
Oecologia. 1980 Apr;45(1):3-10. doi: 10.1007/BF00346699.
Seedlings of Betula pendula Roth. and Gmelina arborea L. were subjected to variation in temperature and irradiance. The influence of a mild water-stressing treatment on the photosynthetic performance and stomatal behaviour of these plants was assessed. For both species, the shape of the relationships between irradiance and photosynthesis and temperature and photosynthesis resembled those reported for other species. The effect of water stress was to reduce the rate of photosynthesis, particularly at high temperatures. This was largely a function of a reduction in mesophyll conductance under these conditions. The optimum temperature for stomatal opening was significantly lower than the optimum temperature for photosynthesis, which was in turn lowered by the water stress treatment. The stomata of birch seedlings showed maximum opening at an intermediate temperature while the stomata of Gmelina generally exhibited a closing movement when leaf temperatures increased from 15° C. Mesophyll conductances of both species increased with increasing temperature.The physiological basis for the variation in photosynthetic performance and stomatal behaviour and the ecological significance of this variation are discussed.
对欧洲白桦（Betula pendula Roth.）和山芝麻（Gmelina arborea L.）的幼苗进行了温度和光照强度变化处理。评估了轻度水分胁迫处理对这些植物光合性能和气孔行为的影响。对于这两个物种，光照强度与光合作用以及温度与光合作用之间的关系形状与其他物种报道的相似。水分胁迫的影响是降低光合作用速率，特别是在高温下。这在很大程度上是这些条件下叶肉导度降低的结果。气孔开放的最佳温度明显低于光合作用的最佳温度，而水分胁迫处理又降低了光合作用的最佳温度。白桦幼苗的气孔在中间温度下显示最大开度，而山芝麻的气孔在叶片温度从15℃升高时通常表现出关闭运动。两个物种的叶肉导度均随温度升高而增加。讨论了光合性能和气孔行为变化的生理基础以及这种变化的生态意义。
