Analysis of the Response of Net Photosynthesis of Rose Leaves of Varying Ages to Photosynthetically Active Radiation and Temperature

Abstract

‘Cara Mia’ rose ( Rosa hybrida L.) leaf net photosynthesis rates were measured at four leaf temperatures over a range of irradiance levels. With the four leaf ages measured, a non-rectangular hyperbola with physiologically meaningful parameters was found to adequately represent the photosynthetically active radiation (PAR) responses. Maximal net photosynthetic rates exhibited a convex pattern with temperature with an optimum between 30 and 37C. The PAR compensation and saturation points both increased with temperature.