Fig. 1
A typical Chl a fluorescence transient from a barley plant grown at optimal conditions. The transient is plotted on a logarithmic time scale from 50 μs to 1 s. The features that give rise to the O-J-I-P designation are highlighted. The marks (dashed lines) refer to the selected fluorescence steps used for the calculation of structural and functional parameters. The signals are: the fluorescence intensity F0 (at 50 μs), the fluorescence intensities FJ (at 2 ms) and FI (at 30 ms) and the maximum fluorescence intensity FP = FM (at tFM). The blue shade under the curve represents the area