Soil and Water Conservation Research Division, ARS, United States Department of Agriculture, United States Water Conservation Laboratory, Phoenix, Arizona 85040.
Plant Physiol. 1968 Feb;43(2):208-14. doi: 10.1104/pp.43.2.208.
Stepwise increases in fluorescent illuminance, imposed as a single variable in a controlled environment, induced progressive stomatal opening in 8 plant species, as evidenced by a consistent decrease in leaf diffusion resistance (R(L)), ranging from 15 to 70 sec cm(-1) in darkness to about 1 sec cm(-1) at approximately 40 kilolux. The minimum R(L) values were the same for the upper and the lower epidermis, provided that stomatal density was adequate. Saturation illuminance was not achieved in any species; extrapolation indicates that 50 kilolux would bring about full stomatal opening (R(L) </= 0.1 sec cm(-1)).In 4 species, reasonable agreement was obtained in a controlled environment between transpiration as measured by weight loss and that calculated from determination of (a) the difference in water vapor density from leaf to air, (b) the boundary layer resistance, and (c) the leaf diffusion resistance. This result confirms the physical validity of the resistance measurement procedure.
在受控环境中，作为单一变量逐步增加荧光照度会导致 8 种植物物种的气孔逐渐打开，这可以通过叶片扩散阻力（R(L)）的持续下降来证明，从黑暗中的 15 到 70 秒 cm(-1) 到大约 40 千勒克斯时约为 1 秒 cm(-1)。只要气孔密度足够，上下表皮的最小 R(L)值是相同的。在任何物种中都未达到饱和照度；推断表明，50 千勒克斯将导致完全打开气孔（R(L) <= 0.1 秒 cm(-1)）。在 4 种植物中，通过重量损失测量的蒸腾作用与通过确定（a）从叶片到空气的水蒸气密度差，（b）边界层阻力和（c）叶片扩散阻力计算得出的蒸腾作用之间在受控环境中得到了合理的一致。这一结果证实了阻力测量程序的物理有效性。
