Chlorophyll Fluorescence, Photoinhibition and Abiotic Stress: Does it Make Any Difference the Fact to Be a C3 or C4 Species?

Chlorophyll fluorescence analysis is one of the most powerful and widely used techniques to study the effect of stresses on the photosynthetic processphotosynthesis and the effects of stresses on this process. From the first utilization, the Fv/Fm ratio has been largely used as a sensitive indicator of plant photosynthetic performance, with optimal values ranging from 0.81 to 0.83 in most plant species. Decreases of this value index are indicative of the reduction of photosystem II (PSII) efficiency, namely photoinhibition. In the last twenty years, application of chlorophyll fluorescence has been largely improved, and many other informative parameters have been established to detect PSII photochemical…