常绿-半常绿杨树苗期光合效率的变化规律

Changes of Photosynthetic Efficiency of Three Evergreen Poplar Clones in Seedling Stage

对3个常绿杨树无性系光合速率日变化及月变化动态进行了研究,结果表明,4月份及6月份,A-65/27及A-65/31的光合速率日变化均呈现明显的双峰型,分别在早上10时左右及午后14时左右达到两次高峰,第二高峰值低于第一个高峰值,A-61/186的光合速率全天只在早上10时左右呈现一个高峰;9、10、11、及12月份3个无性系在早上达到一个峰值后,光合速率开始下降,一天中再没有回升.3个无性系光合速率月变化均呈现明显的单峰型,7月份光合速率达到一年中的最高值,而后开始下降,12月份时降到一年当中的最低值.

Diurnal variation and seasonal variation of Photosynthetic efficiency in three evergreen poplar clones were studied. Results showed that, Photosynthesis diurnal variation of A-65/27and A-65/31 shows two apex values every day in April and June,it appeares at 10 o＇clock and 14 o＇clock or so respectively,and the second value is lower than the first one. A-61/186 have only one apex value,it appeares at 10 o＇clock or so; There is only one apex value for three clones in September, October, November and December. Photosynthesis seasonal variation of three clones both appeared one apex value in July,and decreased to the lowest value in December.