黄褐毛忍冬光合特征和水分利用效率日变化研究

利用Li-6400便携式光合作用测定仪对夏季自然条件下黄褐毛忍冬的光合速率、蒸腾速率、气孔导度和水分利用效率及相应环境因子进行测定.结果表明,黄褐毛忍冬蒸腾速率日变化呈双峰曲线,光合速率的日变化为单峰曲线,并受到光照强度、大气温度、大气相对湿度等环境因子综合作用的影响,其中温度对蒸腾速率的影响最大,相关系数为0.752,光照强度对光合速率的影响最大,相关系数为0.759,气孔开度的日进程与蒸腾速率日进程趋势相一致;黄褐毛忍冬水分利用效率最高值出现在上午8:00左右.

DIURNAL COURSE OF PHOTOSYNTHESIS CHARACTERISTICS AND WATER UTILIZATION EFFICIENCY OF LONICERA FULVOTOMENTOSA

The photosynthesis rate,transpiration rate,stomatal conductance and water utilization efficiency of Lonicera fulvotomentosa were measured with portable Li-6400 gas analysis system under natural summer conditions.The results show that its diurnal variation of transpiration rate is looked like a double-peak curve,photosynthesis rate like a single peak curve,which are affected by illumination,air temperature,air relative humidity,and so on.Moreover,temperature shows the most extraordinary effect on the transpiration rate with the correlation coefficient of 0.752.Illumination influences photosynthesis rate to the great extent with the correlation coefficient of 0.759.The diurnal variation of the stomatal opening stages is coincident to transpiration rate.The largest value of its water utilization efficiency appears at eight o'clock in the morning.