Fig. 5

Comparison of the relative root elongation rate (RER) between the different image acquisition methods. Each circle represents RER for one root. Differences in shading intensity of circles indicate that one or more data points are superimposed. There were no significant differences in RER between the four methods. Each circle represents diameter data for one root. Differences in shading intensity of circles indicate that one or more data points are superimposed. The lower edge of the box corresponds to the 25th percentile (Q1) data point, while the top edge of the box corresponds to the 75th percentile data point (Q3). The line within the box represents the median and the whiskers indicate the range of the data. The two horizontal dashed lines represent an interval of 10% above and below the median of the reference method (flatbed scanner). Different letters above the boxplots indicate statistically significant differences (p < 0.05) between methods