Technical advance: Extracting multiple interacting root systems using X-ray CT

Example of two wheat plants extracted from CT data

Using a combination of X-ray CT and innovative image analysis techniques our research team have successfully demonstrated a method to investigate the 3D architecture of multiple interacting root systems within the soil environment non-destructively. Root system interaction and competition for resources is an important research area that contributes to our understanding of roots’ perception and reaction to environmental conditions as they grow and develop in soil. However, a limitation in using X-ray CT alone in such studies is that due similarities in the X-ray attenuation coefficient of organic material, the roots of different plants appear as similar greyscale intensity values in μCT image data. Unless they are manually and carefully traced, it has previously not been possible to automatically label and separate different root systems grown in the same soil environment. This new technique, based on a visual tracking approach, exploits knowledge of the shape of root cross-sections to automatically recover 3D descriptions of multiple, interacting root architectures growing in soil from X-ray μCT data. The method was evaluated on both simulated root data and real images of two interacting winter wheat Cordiale (Triticum aestivum L.) plants grown in a single soil column, demonstrating that it is possible to automatically segment different root systems from within the same soil sample. This work supports the automatic exploration of supportive and competitive foraging behaviour of plant root systems in natural soil environments. A full report of the work is published online in The Plant Journal http://onlinelibrary.wiley.com/doi/10.1111/tpj.13047/abstract