Abstract: All the five tested tobacco cultivars and lines exhibited a similar "double peak" diurnal curve of photosynthetic rate. This would be caused by a coaction of high atmospheric humidity, feasible air temperature and high light intensity. The change of air temperature and CO₂ concentration did not alter the diurnal curve of photosynthetic rate in some extent.

Key words: tobacco, photosynthesis, diurnal variation

摘要： 在高海拔地区(昆明)对5个品种(系)烟草光合作用日变化的研究结果表明,所有供试材料的净光合速率表现为不显著的"双峰型"曲线。其主要原因可能是较高的空气湿度、相对适宜的温度和强光的综合影响;一定范围内的温度和CO₂浓度变化对光合作用的日变化未能产生明显的影响。

关键词: 昆明, 高海拔地区, 烟草, 光合作用, 日变化