In addition to measuring root growth in soil, another utility of X-ray imaging is that it can be used to image and measure the whole of any complicated structure, including data on its internal anatomy. In this video, optical 2-D dimensional slices of the X-ray CT reconstruction are shown along 2-planes that highlight the geometry, topology, and internal organization of a maize root.
Displayed is a mature maize / corn root crown that has been excavated with a shovel and imaged using X-ray Computed Tomography (XRT or X-ray CT). The root crown (the portion of the root system interfacing just above and just below the soil), represents an information-rich sample since all of the major root axes of the plant originate here. Analysis of the root crown provides valuable data about the likely structure of the root system far below the soil surface, which is much more difficult to capture. Even with 3D imaging, measuring complicated structures such as root crowns is difficult. Typically, hand measurements or 2-D images are used, but fail to capture all of the available information and thus may lack robust phenotypic information.