Differing nodal structure in oat and wheat

Abstract The tube-like structure of grass stems is the most efficient geometric design to resist buckling or breaking. Further stem flexibility and strength is conferred with cross linkages, nodes, within the tube. Weather, specifically wind, can be a factor that can affect the efficiency of the tubal structure resulting in lodging. However, not all grass stems are equally resistant to outside forces such as weather. In this report we visualized internal structures of oat and wheat stems using micro-CT imagery to determine if any differences were present. Wheat, which is more resistant to stem buckling than oat, had thinner nodal tissue with larger air pockets. These structures may allow for more flexibility in the nodal region. Additionally, the internode section of wheat exhibits deeper grooves on the outside of the stem wall, which is hypothesized to allow for more torsion flexibility in response to wind. These physical structures could be utilized to differentiate between lodging types within species.