Effects of temperature, oxygen concentration, leaf age and seasonal variations on the CO2 compensation point of Lolium perenne L. : Comparison with a mathematical model including non-photorespiratory CO2 production in the light.

Various factors affect the CO2 compensation point of detached leaves of Lolium perenne L. These include oxygen concentration, temperature, leaf age, and season (spring and summer). Analysis of the results using the model of G.D. Farquhar, S. von Caemmerer and J.A. Berry (1980) Planta 149, 78-90, indicates that some of the CO2 evolved by leaves in the light is derived from sources other than photorespiration. It is suggested that the operation of the tricarboxylic acid in the light can account for most of this CO2.