Fluorescence parameters | Description |
---|---|
F t | Fluorescence intensity at time t after onset of actinic illumination |
F 50 μs | Minimum reliable recorded fluorescence at 50 μs with the PEA fluorimeter |
Fk (F300 μs) | Fluorescence intensity at 300 μs |
F P | Maximum recorded (= maximum possible) fluorescence at P-step |
Area | Total complementary area between fluorescence induction curve and F = Fm |
ABS | Absorption of energy |
TR | Trap of energy |
CS | Excited Cross section |
Derived parameters (Selected OJIP parameters) | |
Fo≅F50 μs | Minimum fluorescence, when all PSII RCs are open |
Fm = FP | Maximum fluorescence, when all PSII RCs are closed |
Vj = (F2 ms -- Fo)/(Fm -- Fo) | Relative variable fluorescence at the J-step (2 ms) |
Vi = (F30 ms -- Fo)/(Fm -- Fo) | Relative variable fluorescence at the I-step (30 ms) |
WK= (F300 μs-- Fo/(Fj-- Fo) | Represent the damage to oxygen evolving complex OEC |
Mo = 4 (F300 μs -- Fo)/(Fm-- Fo) | Approximated initial slope of the fluorescence transient |
Yields or flux ratios | |
Ï•Po = TRo/ABS = 1-- (Fo/Fm) = Fv/Fm | Maximum quantum yield of primary photochemistry at t = 0 |
ϕEo = ETo/ABS = (Fv/Fm) × (1 -- Vj) | Quantum yield for electron transport at t = 0 |
ψEo = ETo/TRo = 1 -- Vj | Probability (at time 0) that a trapped exciton moves an electron into the electron transport chain beyond QA- |
δRo = (1 -- Vi)/(1 -- Vj) | Efficiency with which an electron can move from the reduced intersystem, electron acceptors to the PSI end electron acceptors |
Density of reaction centers. RCQA = ϕPo × (ABS/CSm) × (Vj/Mo) | Amount of active PSII RCs (QA-reducing PSII reaction centers) per CS at t = m |