Fig. 4.  a) Genotype mean values (± SE) (left panel) and effect size plot (right panel) illustrating the effects of ploidy level and defoliation on net photosynthesis (Amax,) in well-watered trees. Mean values are shown for eight different diploid and triploid genotypes when defoliated or undefoliated. Data points are horizontally jittered to reduce overlapping. The corresponding effect size plots show the relative explanatory importance of each fixed effect as the partial R2 value and the proportion of variance explained by each random effect in the trait model. Asterisks indicate statistical significance (p< 0.050). Statistics for fixed effects and random intercepts are shown in the supplementary data Table S2. b) Photosynthesis drought response curves of defoliated and undefoliated diploid and triploid genotypes. Red trends were generated based on back-transformed means of ln-transformed genotype values for each of the curve-fitting parameters (Amax, b and c). Transformation of genotype parameters lessened the undue influence of outlier values. Thin curves represent untransformed, individual genotypes (raw data shown in the supplementary data Fig. S4). The impact of ploidy, defoliation and their interaction on the curve parameters Amax, b and c was tested in models accounting for genotypic differences. Only values of model variables with P ≤ 0.100 are shown.