A New Open Gas-Flow System Configuration for Measurement of Photosynthetic CO2 Response Curve

Gasometric methods employing an infra-red gas analyser (IRGA) have been widely used for determining photosynthetic CO2 uptake, both in the laboratory and in the field. Generally, gas-exchange measuring systems may be classified into 3 basic types: closed, semi-closed and open (for more detailed description see [1] and [2]). A serious methodical objection to a closed system is that since CO2 concentration continuously changes, steady-state observation cannot be obtained. On the other hand, this fact can be exploited in dynamic studies and modelling of photosynthesis [3]. Open system measurement have recently been commonly used, especially in studies based on the assumption of a steady-state condition [4].