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

Abstract

The calculated maximum net photosynthetic rate (PN) at saturation irradiance (Im) of 1 314.13 μmol m-2 s -1 was 25.49 μmol(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 PN values calculated by nonrectangular hyperbolic model and rectangular hyperbolic model were higher than the measured values, and the Im 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 PN to I was nonlinear at low I for Oryza sativa, PN increased nonlinearly with I below saturation value. Above this value, P N decreased nonlinearly with I. © 2007 Institute of Experimental Botany, ASCR.