Table 3.

Abbreviations, definitions and formulas of the chlorophyll fluorescence parameters assessed in the current study.

Category	Abbreviation	Definition	Equation
Basic parameters	F0	Minimum fluorescence, when all PSII reaction centers are open (O-step of OJIP transient)	F50µs
	FJ	Fluorescence intensity at the J-step (2 ms) of OJIP	F2ms
	FI	Fluorescence intensity at the I-step (30 ms) of OJIP	F30ms
Fluorescence parameters	Fm	Maximum fluorescence, when all PSII reaction centers are closed (P-step of OJIP transient)	F1s = Fp
	Fv	Variable fluorescence of the dark-adapted sample	Fm – F0
	VJ	Relative variable fluorescence at time 2 ms (J-step) after start of actinic light pulse	(FJ – F0)/(Fm – F0)
	VI	Relative variable fluorescence at time 30 ms (I-step) after start of actinic light pulse	(F30ms – F0)/(Fm – F0)
	Fv/Fm	Maximal quantum yield of PSII photochemistry	1 – (F0/Fm) = (Fm – F0)/Fm = φP0 = TR0/ABS
Quantum yields and efficiencies/probabilities	φE0	The quantum yield of electron transport	[1– ( F0/ Fm)](1 – VJ) = ET0/ABS
	φD0	Quantum yield of energy dissipation	F0/Fm
	φPAV	Average (from time 0 to tFM) quantum yield for primary photochemistry	φP0 (1 − VJ) = φP0 (SM/tFM)
Specific energy fluxes (per QA reducing PSII reaction center)	ABS/RC	The specific energy fluxes per reaction center for energy absorption	M0 (1/VJ)(1/φP0)
	TR0/RC	Trapped energy flux (leading to QA reduction) per reaction center	M0 (1/VJ)
	ET0/RC	Electron transport flux (further than QA−) per reaction center	M0 (1/VJ)(1 − VJ)
	DI0/RC	Dissipated energy flux	(ABS/RC) − (TR0/RC)
Performance indices (products of terms expressing partial potentials at steps of energy bifurcations)	PIABS	Performance index for the photochemical activity	[(γRC/1 − γRC)( φP0 /1 − φP0)(ψE0 /1 − ψE0)]
	NPQ	Non-photochemical quenching	(Fm/Fm´) – 1
Rapid light curve as a function of PPFD	ΦPSII	Effective quantum yield of PSII	∆F/Fm´ = (Fm´ – F)/ Fm´
	rETR	Relative electron transport rate	ΦPSII × PPFD × 0.5 × 0.84