An integrated fluorometer or better integrated chlorophyll fluorometer is a device used to measure parameters of gas exchange and chlorophyll fluorescence of a leaf. These parameters are used to non destructively measure the photosynthetic efficiency of plants. Parameters typically measured are the photosythetic rate, stomatal conductance, sub stomatal CO2 concentration, mesophyll conductance, dark respiration in the light, Γ* CO2 compensation point and CO2 at the site of carboxylation.
Components and Design
Typically, integrated chlorophyll fluorometers consist of a leaf chamber in which the sample to be measured is sealed. Inside may be a thermistor to monitor the air and leaf temperature and a PAR sensor to measure the photosynthetically active radiation (400-700 nm) reaching the surface of the leaf. This chamber is part of an gas exchange system, typically used to measure photosynthesis and transpiration of leaves. For more information please visit the article photosynthesis systems.
A highly specialized light unit is held over the clear window of the chamber. This not only supplies the light to drive the photosynthesis of the leaf but also houses a sensitive chlorophyll fluorometer.
Although highly complex, modern systems are relatively compact, portable and easy to use. With modern battery technology, it is normal for integrated chloropyhll fluorometers to operate for 8 hours in the field before recharging is necessary.
Integrated chloropyhll fluorometers are being used by leading plant physiologists to probe the photosynthetic process in plants. The results of this research will enable scientists to improve the efficiency of CO2 utilization by crops and estimate the capacity of grasslands, forests and ecosystems to mitigate climate change. It is hoped that these devices will enable us to screen genetic mutants to identify plants with an increased capacity to assimilate CO2.
- Photosynthesis system, for more information about gas exchange measuring systems
- Chlorophyll fluorescence, to investigate plant ecophysiology.
- Microfluorimetry, to measure fluorescence on a microscopic level