Table 1.
Parameters, formulae and their description using data extracted from chlorophyll (Chl) a fluorescence (OJIP) transient emitted by dark-adapted photosynthetic samples (Yusuf et al., 2010).
| Fluorescence parameters | Description |
|---|---|
| EXTRACTED PARAMETERS | |
| Ft | Fluorescence at time t after onset of actinic illumination |
| Fo | Minimum fluorescence, when all PSII reaction centers (RCs) are open |
| Fm | Maximum fluorescence, when all PSII RCs are closed |
| F50μ 4s, F100μ 4s, F300 4μ 4s | Fluorescence intensity at 50, 100, and 300 μs, respectively |
| FJ | Fluorescence intensity at the J-step (2 ms) |
| FI | Fluorescence intensity at the I-step (30 ms) |
| Area | Total complementary area between fluorescence induction cure and F = Fm |
| TECHNICAL FLUORESCENCE PARAMETERS | |
| Vt4 = (Ft − Fo)/(Fm − Fo) | Relative variable fluorescence at time t |
| VJ4 = (F2ms − Fo)/(Fm − Fo) | Relative variable fluorescence at the J-step (2 ms) |
| VI4 = (F30ms − Fo)/(Fm − Fo) | Relative variable fluorescence at the I-step (30 ms) |
| Mo4 = 4 (F300 μ4s – Fo)/(Fm – Fo) | Approximated initial slope (in ms−1) of the fluorescence transient V = f (t) |
| QUANTUM YIELDS AND EFFICIENCIES/PROBABILITIES | |
| φPo4 = TRO/ABS = 1–(FO/Fm) | Maximum quantum yield for primary photochemistry |
| ψEo4 = ETO/TRO4 = 1–VJ | Effciency/probability with which a PSII trapped electron is transferred from QA to QB |
| δRo = 4REO/ETO = (1–VI)/(1–VJ) | Efficiency/probability with which an electron from QB is transfered uuntil PSI acceptors |
| SPECIFIC ENERGY FLUXES (PER ACTIVE PSII REACTION CENTER) | |
| ABS/RC = Mo(1/VJ)(1/φPo) | Absorbed photon flux per RC |
| TRo/RC = Mo(1/VJ) | Trapped excitation flux (leading to QA reduction) per RC |
| ETo/RC = Mo(1/VJ) ψEo | Electron transport flux (further than Q−A) per RC |
| REo/RC = Mo(1/VJ) ψEo 4δ4Ro | Electron flux reducing end electron acceptors at the PSI acceptor side, per RC |