四季桂光合特性的季节变化研究

Seasonal Changes of Photosynthetic Characteristics of Houses Ornamental Plant Osmanthus fragrans var.semperflorens

采用LI-6400光合测定仪测定四季桂光响应曲线和光合特性的季节变化。结果表明,四季桂叶片的光响应曲线变化趋势基本一致,净光合速率和光补偿点由低到高依次为1月<4月<10月<7月,光饱和点依次为7月<10月<4月<1月。四季桂叶片Pn、Tr、VPD、Gs的日变化表现为1月和4月均为单峰曲线,10:00达到峰值;7月和10月均为"双峰型",具有明显的光合"午休"现象。1月,Ci持续下降;4月Ci先逐渐下降,15:00出现小峰值;10月和7月,Ci在10:00最低,15:00达到峰值。

The seasonal changes of light response curve and photosynthetic characteristics of Osmanthus fragrans var. semperflorens were determined by LI-6400. The results showed that the light response curve changes of O. fragrans var. semperflorens＇s leaves at different seasons were similar. The net photosynthetic rate and light compensation point were Jan〈Apr〈Oct〈Jul, and the light saturation point was Jul〈Oct〈Apr〈Jan. The day changes of Pn, Tr, VPD and Gs of O. fragrans var. semperflorens were single peak curve separately at January and April, while double peak curve and had photosynthetic ＂lunch-break＂ atmosphere at July and October. The seasonal change of Ci was that Ci decreased continuously at January, while decreased first and then reached a small peak value at 15：00 at April, and appeared the lowest point at 10：00 and the highest point at 15：00 at July and October.