RHIZOSCAN: A semiautomatic image processing system for characterization of the morphology and secondary metabolite...

We describe the application of the newly developed RHIZOSCAN software for accurate morphological analysis and determination of overall and local secondary metabolite concentrations in two clones of Beta vulgaris throughout the growth period. Local secondary metabolite concentrations may be determined at any point in the root, and pigment gradients in each lateral root can be followed during culture and saved to the computer. Throughout the entire analysis process, an image appears in a graphical result window on the screen, which enables visual evaluation of the numerical output at each stage of the analysis. Biosynthetic data on concentrations obtained by image analysis were validated by spectrophotometric analysis. The importance of determining appropriate scanning and analysis conditions (scanning resolution, background color, threshold value, segmentation plane in the hue-saturation-intensity color system and pruning length) for obtaining accurate morphological measurements is examined and the means of fixing these parameters is described. Our results show that, using RHIZOSCAN, detailed and accurate information on root architecture and secondary metabolite concentrations can be obtained in a short time.