Table 2.

Photosynthetic parameters deduced by the JIP-test analysis fluorescence transients.

Photosynthetic parameters	SM			RM			Definitions
	CK	LT	LTA	CK	LT	LTA
Specific energy fluxes (per active PS II reaction center)
ABS/RC	3.05b	3.64a	3.24b	2.90c	3.58a	3.28b	Absorbed photon flus per RC
TR0/RC	2.24c	2.67a	2.50b	2.19b	2.08c	2.39a	Trapped excitation flux(leading to QA reduction) per RC
ET0/RC	1.07b	1.35a	1.18b	1.08b	1.04c	1.22a	Electron transport flux(further than QA-) per RC
RE0/RC	0.42c	0.74a	0.61b	0.47b	0.52a	0.45c	Electron flux reducing end electron acceptors at the PS I acceptor side, per RC
Quantum yields and efficiencies/probabilities
φP0	0.73a	0.67c	0.70b	0.75a	0.65c	0.68b	Maximum quantum yield for primary photochemistry, namely FV/FM
φE0	0.34a	0.31b	0.34a	0.37a	0.33b	0.34b	Quantum yield of the electron transport flux from QA to QB
	0.24a	0.21c	0.22b	0.25a	0.21c	0.22b	Probability that a PS II Chl molecule functions as RC
Performance Indexes (PI, combination of parameters)
PIABS	0.62a	0.38b	0.65a	0.99a	0.56c	0.64b	PI(potential) for energy conservation from exciton to the reduction of intersystem electron
PItotal	0.54b	0.49c	0.73a	0.77a	0.45c	0.56b	PI(potential) for energy conservation from exciton to the reduction of PS I end acceptors

The calculation of each parameter is based on the method described by Yusuf et al. (2010). Subscript “0” indicated that the parameter refers to the onset of illumination. Values are given as the average of 3 replicates, and different letters indicated statistical difference significance at P < 0.05 among the treatments by Ducan’s multiple range tests. The CK represents control treatment at the optimum temperature (28/24°C, day/night). LT refers to cold treatment at a temperature of 4°C (day/night). LTA represents the treatment that treated with 100 μM ABA solution at a temperature of 4°C (day/night). S and R represented cold-sensitive and cold-resistance Bermudagrass genotype, respectively.