白兰花秋季光合特性研究

The Photosynthetic Characteristics of Michelia alba in Autumn

采用Li-6400型便携式光合作用测定系统测定了白兰花的光合特性。结果表明:白兰花净光合速率日变化呈双峰曲线,存在光合"午休"现象。最高峰出现在14:00左右,次高峰出现在9:00,日最大净光合速率为5.22μmol.m-2.s-1。净光合速率与蒸腾速率、气孔导度呈正相关,与胞间CO2浓度呈负相关。白兰花的光补偿点为10.38μmol.m-2.s-1,光饱和点为1 100μmol.m-2.s-1,具有一定的耐荫能力,是不耐强光的植物。

The photosynthetic characteristics study of leaves in perennial evergreen arbor Michelia alba were determined with the Li-6400 Photosynthetic system. The results showed that the curve of daily of M. alba net photosynthetic rate was a double-peak curve and there was a clear depression at noon. Its first peak occurred at 14：00 p. m. , the second one at 9：00 a. m.. The maximum of photosynthetic rate was 5.22μmol·m-2·s-1. Correlation analysis showed that there were positive relationship between photosynthetic rate and transpiration rate and stomatal conductance, there is a negative relationship between photosyn- thetic rate and internal CO2 concentration. The light compensation point of M. alba is 10.38 μmol·m-2·s-1, its light saturation point is 1 100 μmol·m-2·s-1. The light compensation and saturation point indicates that M. alba is a little shade-resistant plant and it cann＇t bear the glare.