McCutchan Cheryl L, Monson Russell K
University of Colorado, Department of Environmental, Organismic, and Population Biology, Campus Box 334, Boulder, CO, 80209-0334.
New Phytol. 2001 Mar;149(3):419-430. doi: 10.1046/j.1469-8137.2001.00039.x.
• The relationship between night-time respiration rate and carbohydrate supply are measured in two alpine perennials, Bistorta bistortoides and Campanula rotundifolia. • Natural populations of B. bistortoides and C. rotundifolia were subjected to high and low light treatments. During the following night, respiration rate and carbohydrate content of leaves were measured. • At the beginning of the dark period, leaf carbohydrate concentrations were significantly lower in plants exposed to lower irradiance on the previous day. The night-time respiration rate in leaves of both species was rarely affected by the previous days' irradiance; over the course of the night, respiration rate remained unchanged in C. rotundifolia and decreased, but not consistently, in B. bistortoides. No significant interaction was found between irradiance and the night-time pattern of carbohydrate concentration or respiration rate. Nocturnal carbohydrate export was positively correlated with the previous days' irradiance in leaves of C. rotundifolia only. • Leaf respiration rate is uncoupled from carbohydrate supply in leaves of B. bistortoides and C. rotundifolia, possibly allowing more carbohydrate to be exported to underground storage organs.
• 对两种高山多年生植物珠芽蓼（Bistorta bistortoides）和圆叶风铃草（Campanula rotundifolia）夜间呼吸速率与碳水化合物供应之间的关系进行了测定。
• 对珠芽蓼和圆叶风铃草的自然种群进行了高光和低光处理。在接下来的夜晚，测量了叶片的呼吸速率和碳水化合物含量。
• 在黑暗期开始时，前一天接受较低光照的植株叶片碳水化合物浓度显著较低。两种植物叶片的夜间呼吸速率很少受到前一天光照的影响；在夜间过程中，圆叶风铃草的呼吸速率保持不变，而珠芽蓼的呼吸速率下降，但并不持续。在光照与碳水化合物浓度或呼吸速率的夜间模式之间未发现显著相互作用。仅在圆叶风铃草的叶片中，夜间碳水化合物输出与前一天的光照呈正相关。
• 珠芽蓼和圆叶风铃草叶片的呼吸速率与叶片碳水化合物供应解偶联，这可能使更多的碳水化合物能够输出到地下贮藏器官。
