Table 1.
Definition of energy fluxes and fluorescence transients parameters were used in the OJIP-test. These parameters are used to analyse the ‘fast’ (<1 s) chlorophyll a fluorescence transient.41
| Technical fluorescence parameters | Meaning |
|---|---|
| FV = FM–FO | Maximum variable fluorescence |
| Vt = (Ft–FO)/FV | Relative variable fluorescence |
| Fo | Minimum fluorescence intensity |
| Fm | Maximum fluorescence intensity |
| M0 = (ΔV/Δt) 0 ≈ 4(F0.3ms–F 0.05ms)/FV | Initial slope (in ms−1) of the O-J fluorescence rise |
| Sm = Area/FV | Normalized area between the OJIP curve and the line F = FM, which is a proxy of the number of electron carriers per electron transport chain |
| Efficiencies and quantum yields | |
| δR0 = ψR0/ψE0 = RE0/ET0 | Efficiency with which an electron from PQH 2 is transferred to final PSI acceptors |
| TR0/ABS = ϕP0 = FV/FM | Maximum quantum yield of primary PSII photochemistry |
| ϕE0 = ET0/ABS = ϕP0× ψE0 | Quantum yield of electron transport from QA to PQ |
| Specific energy fluxes (per active PSII) | |
| ABS/RC = (M0/VJ)/ϕP0 | Apparent antenna size of an active PSII |
| TR0/RC = M0/VJ | Maximum trapped exciton flux per active PSII |
| ET0/RC = (M0/VJ)×ψE0 | The flux of electrons transferred from QA to PQ per active PSII |
| RE0/RC = (M0/VJ)×ψR0 | The flux of electrons transferred from QA to final PSI acceptors per active PSII |
| DI0/RC = ABS/RC–TR0/RC | The flux of energy dissipated in processes other than trapping per active PSII |
| Quantum efficiencies, flux ratios | |
| ϕP0 | Quantum yield of the QA reduction ϕP0 = (1−F0)/FM = TR0/ABS |
| ϕE0 | Quantum yield of the electron transport beyond QA ϕE0 = (1−F0/FM)ψ0 = ET0/ABS |
| Ψ0 | Probability that a trapped exciton is used for electron transport beyond QA. ψ0 = 1−VJ = ET0/TR 0 |
| Performance Index and derived parameters | |
| PIABS | Performance Index on absorption basis. PI abs = RC/ABS [ϕP0/(1−ϕP0)] [ψ0/(1−ψ0)] |
| PIABS,total = PIABS × [δR0/(1–δR0)] | Total performance index on absorption basis |