Abstract:

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 CO2 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.