Brix H
Department of Forestry and Rural Development of Canada, Forest Research Laboratory, Victoria, B.C., Canada.
Plant Physiol. 1968 Mar;43(3):389-93. doi: 10.1104/pp.43.3.389.
The rate of photorespiration of Douglas-fir seedlings was measured under different light intensities by: (1) extrapolating the curve for CO(2) uptake in relation to atmospheric CO(2) content to zero CO(2) content, and (2) measuring CO(2) evolution of the plants into a CO(2)-free airstream. Different results, obtained from these techniques, were believed to be caused by a severe restriction of the photosynthetic activity when the latter was used. With the first method, CO(2) evolution was lower than the dark respiration rate at low light intensity. For all temperatures studied (6 degrees , 20 degrees , 28 degrees ) a further increase in light intensity raised the CO(2) evolution above dark respiration before it leveled off. The rate of CO(2) evolution was stimulated by increase in temperature at all light intensities. With the CO(2)-free air method, CO(2) evolution in the light was less than dark respiration at all light intensities.
(1) 将二氧化碳吸收量相对于大气二氧化碳含量的曲线外推至零二氧化碳含量，以及(2) 测量植物向无二氧化碳气流中释放的二氧化碳量。人们认为，使用后一种技术得到的不同结果是由光合活性受到严重限制导致的。使用第一种方法时，在低光照强度下，二氧化碳释放量低于暗呼吸速率。对于所有研究的温度（6摄氏度、20摄氏度、28摄氏度），光照强度进一步增加会使二氧化碳释放量在趋于平稳之前高于暗呼吸速率。在所有光照强度下，温度升高都会刺激二氧化碳释放速率。使用无二氧化碳空气法时，在所有光照强度下，光照下的二氧化碳释放量都低于暗呼吸。
