Table 2.

The gas exchange parameters and chlorophyll pigment concentrations in male and female leaves of P. cathayana as affected by temperature (25, 15, and 4 °C)

Parameters	25 °C males	25 °C females	15 °C males	15 °C females	4 °C males	4 °C females	Fs	Ft	Fs×t
Pn (μmol m−1 s−1)	16.19±0.75 bc	16.79±0.70 c	15.72±0.64 bc	13.90±0.50 b	2.99±0.13 a	1.10±0.19 a	0.027*	0.000**	0.059
gs (mol m−1 s−1)	0.45±0.01 d	0.51±0.05 d	0.44±0.02 cd	0.34±0.02 c	0.17±0.01 b	0.04±0.00 a	0.035*	0.000**	0.017*
Ci (μmol mol−1)	400.29±4.97 a	406.67±7.60 ab	416.97±7.41 ab	419.44±3.90 ab	433.13±6.79 bc	445.33±6.22 c	0.304	0.001**	0.836
E (mmol m−1 s−1)	5.98±0.10 d	6.44±0.24 d	3.19±0.27 c	2.96±0.24 c	1.72±0.11 b	0.66±0.07 a	0.188	0.000**	0.021*
Chl a (mg g−1 Fw)	25.60±1.18 bc	25.44±1.01 bc	25.99±0.92 c	25.89± 1.17 c	24.11±1.32 b	20.98±0.79 a	0.002**	0.000**	0.001**
Chl b (mg g−1 Fw)	20.08±1.16 c	15.39±0.71 b	14.25±0.72 b	15.62±0.77 b	8.78±0.15 a	5.98±0.39 a	0.014*	0.000**	0.001**
Caro (mg g−1 Fw)	4.04±0.11 a	4.30±0.25 ab	4.57±0.35 ab	3.66±0.14 a	5.79±0.19 b	5.59±0.33 b	0.174	0.000**	0.125
Chl (mg g−1 Fw)	45.70±1.08 d	40.82±0.70 c	40.26±1.14 c	41.42±0.94 cd	32.86±0.31 b	26.97±1.18 a	0.001**	0.000**	0.001**
Chl a/b	1.28±0.83 a	1.66±0.08 ab	1.85±0.15 b	1.65±0.04 ab	2.75±0.07 c	3.52±0.10 d	0.002**	0.000**	0.000**

Each value is the mean ±SE. F_s, sex effect; F_t, temperature effect; F_s×t, sex and temperature interaction effect; Fw, fresh weight; *, 0.01<P ≤0.05; **, P ≤0.01.