Figure 5.

Excess light-acclimated T2 exhibits a faster rise in quantum yield of photosystem II (Φ_PSII), and/or higher maximum Φ_PSII, than its diploid progenitors under NPQ measurement conditions (2000 μmol m⁻² s⁻¹ light intensity, 0% CO₂, 2% O₂). Under the general linear model (GLM), the main effect of light treatment had a significant effect on Φ_PSII (F_1,14=287.513, P<0.001), but species (F_2,14=1.055, P=0.374), and the interaction of treatment and species (F_2,14=2.629, P=0.107) were not significant. A single-factor analysis of variance testing the effect of species on Φ_PSII under EL did detect a significant effect (F_2,7=5.229, P=0.041). (a) Initial rise in Φ_PSII during the first minute of illumination for plants grown under LL. (b) Initial rise in Φ_PSII during the first minute of illumination for plants grown under EL. (c) Maximum Φ_PSII achieved during NPQ measurement for plants grown under LL (D4L, D3L, T2L) and EL (D4E, D3E, T2E). Letters above columns indicate statistical significance between samples under the GLM—categories not sharing a letter differ significantly at P<0.05 (Tukey's HSD). White letters inside the EL columns indicate statistical significance between species within EL based on a single-factor analysis of variance comparing differences among species under EL (Tukey's HSD). In all the three panels, error bars represent s.e. (N=3 (D3 and D4) or 4 (T2)).