Table 3.

Photosynthetic parameters of PI curves (O₂) of the purple and green morph of Zygogonium AUT and Zygogonium SCOT, calculated by using the fitting models of Walsby 1997 (‘green morphs’) or Webb, Newton and Starr 1974 (‘purple morphs’).

	α	Ic	Ik	Pmax	R
Zygogonium AUT-p	11 ± 2.64a	12.99 ± 2.02a	28.42 ± 5.23a	315.5 ± 28.38a	−161.93 ± 15.3a
Zygogonium AUT-g	13.12 ± 2.17a	11.77 ± 0.95a	16.76 ± 2.99b	113.86 ± 14.79b	−134.57 ± 12.72b
Zygogonium SCOT-p	7.89 ± 1.27b	7.5 ± 1.27b	29.79 ± 8.01a	148.95 ± 18.08c	−69.48 ± 6.64c
Zygogonium SCOT-g	9.23 ± 1.83b	8.08 ± 0.95b	11.17 ± 1.12b	103.81 ± 12.89b	−74.36 ± 11.64c

Different lower case letters indicate significant differences between the values (α, I_c, I_k, P_max or R) of the four different groups. They were determined by one-way ANOVA followed by Tukey's post hoc test (P < 0.05). α initial slope in the light-limiting range (μmol O₂ h⁻¹ mg⁻¹ chl. a (μmol photons m⁻² s⁻¹)-1), I_c light compensation point (μmol photons m⁻² s⁻¹), I_k initial value of light-saturated photosynthesis (μmol photons m⁻² s⁻¹), P_max maximum photosynthetic rate in the light-saturated range (μmol O₂ h⁻¹ mg⁻¹ chl. a), R respiration rate in the dark (μmol O₂ h⁻¹ mg⁻¹ chl. a).