不同光照处理对野扇花光合日变化的影响

为了解野扇花叶片在不同光照处理下光合作用特征及生长的适宜生态条件，采用Li-6400型便携式全自动光合作用测定系统对不同光照处理的野扇花叶片净光合速率及相关因子进行测定。结果表明：（1）随着遮光程度的增加，净光合速率、蒸腾速率和气孔导度逐渐降低，胞间CO2浓度逐渐升高。（2）野扇花净光合速率控制因子为气孔限制和非气孔限制共同作用。（3）60%和30%遮光处理下净光合速率与环境光合有效辐射的日变化趋势相符合，85%遮光和全光照处理下净光合速率未随环境光合有效辐射的变化而明显变化。（4）不同光照处理下影响净光合速率的主要环境因子不同。建议适度遮光，避免光抑制，同时应注意适宜的株行距，以促进通风，提高胞间CO2浓度，有利于光合作用进行和野扇花的正常生长。

Effect of Different Light Treatment on Photosynthetic Diurnal Changes of Sarcococca ruscifolia Stapf

In order to understand the eco-physiological characteristics and its suitable ecological condition of Sarcococca ruscifolia Stapf,the diurnal variation of photosynthetic characteristics and its relationship to the environmental factors of Sarcococca ruscifolia Stapf under different shading treatment were studied with the Licor-6400 portable photosynthetic system.The results showed as following：（1） with the increase of shading,the Pn,Tr （transpirationrate） decreased significantly,while the Ci （intercellular CO 2 concentration） increased markedly.（2） Sarcococca ruscifolia Stapf＇s controlling factor of photosynthetic rate was stomatal limitation and non-stomatal limitation.（3） the trends of diurnal changes of Pn and PAR （photo available radiation） were consistent in the 30% and 60% of full light conditions,but the Pn didn＇t change with the PAR in the 85% treatment and full light condition.（4） the important environmental factors impacting on Pn were varied in different light conditions.Thus moderate shading was necessary to avoid photoinhibition,and the appropriate spacing was kept to facilitate ventilation for increasing Ci concentration which is benefit for the photosynthesis and growth of Sarcococca ruscifolia Stapf.