Fig. 1

– Phenotype frequency plots for the four traits measured. Including the observed means from year 1 and year 2 for grain Fe concentration (a and b, respectively) and the corrected means (best linear unbiased predictions) for Fe bioavailability in year 1 and year 2 (c and d, respectively). The MAGIC founder values for each trait are overlaid on each histogram, signified by a text label. In year 1 all founders were measured, while only two founders (Claire and Robigus) were measured in year 2. Also shown is a graphical correlation matrix for the bioavailability line means and the observed Fe concentration means from both years (e). Correlations left blank signify that the P value associated with the Pearson’s correlation test was greater than P = 0.01. The correlation matrix was plotted using the R package “corrplot” [36]. The trend between the Fe concentration means from year 1 (Y1) and year 2 (Y2) is also shown as a scatter plot with the Pearson’s correlation test results overlayed on the plot (f)