A new model for relationship between irradiance and the rate of photosynthesis in Oryza sativa

The calculated maximum net photosynthetic rate (P-N) at saturation irradiance (I-m) of 1 314.13 mu mol m(-2) s(-1) was 25.49 mu mol(CO2) m(-2) s(-1), and intrinsic quantum yield at zero irradiance was 0.103. The results fitted by nonrectangular hyperbolic model, rectangular hyperbolic method, binomial regression method, and the new model were compared. The maximum P-N values calculated by nonrectangular hyperbolic model and rectangular hyperbolic model were higher than the measured values, and the I-m calculated by nonrectangular hyperbolic model and rectangular hyperbolic model were less than measured values. Results fitted by new model showed that the response curve Of P-N to I was nonlinear at low I for Oryza sativa, P-N increased nonlinearly with I below saturation value. Above this value, P-N decreased nonlinearly with I.