Table II.

Correlation coefficients and probabilities for plant attributes linked to the first principal components for photosynthetic parameters concerned with temperature acclimation

Variables taken into account are as follows: the differences in Opt (A₃₆₀) depending on growth temperature [ΔOpt (A₃₆₀)], the ratio of J_max/V_cmax at 25°C for 15°C plants to that at 25°C for 30°C plants (J_max/V_cmax ratio at 25°C), the ratio of leaf mass per area for 15°C plants to that for 30°C plants (LMA), the ratio of nitrogen content per unit area for 15°C plants to that for 30°C plants (N_area), the ratio of Rubisco content for 15°C plants to that for 30°C plants (Rubisco content), the ratio of A₃₆₀ at 15°C for 15°C plants to that at 30°C for 30°C plants (A₃₆₀ at the growth temperature), the ratio of Rubisco k_cat activity at 15°C for 15°C plants to that at 30°C for 30°C plants (Rubisco k_cat activity at the growth temperature), the ratio of R_d at 15°C for 15°C plants to that at 30°C for 30°C plants (R_d at the growth temperature), and the ratio of NAD-ME activity at 15°C for 15°C plants to that at 30°C for 30°C plants (NAD-ME activity at the growth temperature). Differences between the mean data for each species were regressed against the scores of Axis 1 and Axis 2. ⁺ P < 0.10, * P < 0.05, ** P < 0.01.

Parameter	Axis 1		Axis 2		Jmax/Vcmax		LMA		Narea		A360		Rubisco		kcat		Rd		NAD-ME
ΔOpt (A360)	−0.73	*	0.57	+	0.79	*	0.57	+	0.53	+	0.53	+	0.73	*	0.00		0.64	*	0.30
Jmax/Vcmax ratio at 25°C	−0.82	**	0.19				0.85	**	0.53	+	0.46		0.68	*	0.39		0.47		0.59	+
LMA	−0.88	**	−0.08						0.63	*	0.50		0.79	*	0.57	+	0.40		0.86	**
Narea	−0.69	*	0.38								0.42		0.75	*	0.08		0.42		0.48
A360 at growth temperature	−0.82	**	−0.17										0.70	*	0.58	+	0.93	**	0.66	*
Rubisco content	−0.91	**	0.23												0.29		0.67	*	0.70	*
kcat at growth temperature	−0.57	+	−0.80	*													0.39		0.85	**
Rd at growth temperature	−0.77	*	0.04																0.51
NAD-ME at growth temperature	−0.84	**	−0.48
Contribution (%)	62.0		16.2