. 2013 Feb 1;64(6):1485–1496. doi: 10.1093/jxb/ert005

Table 4.

Yield (F _v’/F _m’), quantum yield (Ф_PSII), photochemical quenching coefficient (q _P), non-photochemical quenching (NPQ), and electron transport rate (ETR) in leaf 3 and leaf 4 of an old (released in 1961) and a modern (released in 1997) winter wheat cultivar exposed to elevated CO₂ and/or O₃ for 21 days in OTCs. Chlorophyll a fluorescence parameters were recorded simultaneously with gas exchange measurement. Leaf chamber environment conditions (i.e. PPFD, temperature, relative humidity, flow rate, and CO₂ concentration) were the same as those used for gas exchange measurement: control (CO₂, 385±4 ppm+CFA, 4±0.02 ppb O₃); elevated CO₂ (CO₂, 714±16 ppm+CFA, 4±0.02 ppb O₃); O₃ (ambient CO₂, 385±4 ppm+elevated O₃, 72±5 ppb O₃ for 7h d^–1, 9.00–16.00h); and elevated CO₂+O₃ (elevated CO₂, 714±16 ppm+elevated O₃, 72±5 ppb for 7h d^–1). Overall, elevated CO₂ significantly increased (P <0.01) Ф_PSII, q_P, and ETR in the young leaf but decreased NPQ in the matured leaf. Elevated O₃ did not alter any light-adapted fluorescence parameter in the young leaf but considerably increased NPQ (P <0.01) in the mature leaf. Results are shown as means±1 standard error (n=8). Means with the same letter were not significantly different.

Treatment	F _v’/F _m’		Ф_PSII		q _P		NPQ		ETR
Treatment	Leaf 3	Leaf 4	Leaf 3	Leaf 4	Leaf 3	Leaf 4	Leaf 3	Leaf 4	Leaf 3	Leaf 4
(a) Beijing 6 (1961)
Control	0.60±0.04	0.50±0.01^a	0.098±0.01^a	0.091±0.00^ab	0.13±0.01^b	0.18±0.01^bcd	2.48±0.02^bc	1.78±0.01^b	46±4^ab	57±3^ab
CO₂	0.62±0.04	0.48±0.01^ab	0.079±0.01^ab	0.095±0.00^ab	0.13±0.01^b	0.20±0.01^abc	2.12±0.02^bc	2.01±0.01^ab	43±4^ab	60±3^ab
O₃	0.54±0.03	0.50±0.01^a	0.072±0.01^ab	0.084±0.01^b	0.13±0.01^b	0.17±0.01^d	4.87±0.02^a	1.93±0.01^ab	46±3^ab	53±3^b
CO₂+O₃	0.57±0.03	0.51±0.02^a	0.070±0.01^ab	0.092±0.00^ab	0.12±0.01^b	0.18±0.01^bcd	2.43±0.02^bc	1.84±0.01^ab	42±3^b	58±3^ab
(b) Zhongmai 9 (1997)
Control	0.51±0.04	0.51±0.01^a	0.052±0.01^b	0.086±0.00^ab	0.10±0.01^b	0.17±0.01^cd	2.41±0.02^bc	1.67±0.01^b	37±5^b	54±3^ab
CO₂	0.59±0.04	0.46±0.01^b	0.103±0.01^a	0.094±0.00^ab	0.18±0.01^a	0.21±0.01^ab	1.93±0.02^c	1.55±0.01^b	57±4^a	59±3^ab
O₃	0.56±0.03	0.51±0.01^a	0.077±0.01^ab	0.082±0.00^b	0.14±0.01^b	0.16±0.01^d	4.54±0.02^ab	1.56±0.01^b	45±4^ab	51±3^b
CO₂+O₃	0.49±0.02	0.46±0.01^b	0.066±0.01^ab	0.098±0.00^a	0.13±0.01^b	0.21±0.01^a	3.16±0.02^abc	2.73±0.01^a	48±5^ab	62±3^a