Morphogenesis and physical characteristics of adventitious roots in edible canna [Japanese]

摘要

In edible canna, the morphological and anatomical features and the physical characteristics of the adventitious roots which generated in pairs simultaneously near the nodes of rhizomes, were examined. The roots at various distances and directions from the stock base were examined in different growth stages. The 'horizontal roots' running shallow underground and the 'vertical roots' growing deep in soil were clearly distinguishable. The roots generated from the basal and apical side of the nodes of rhizome developed to 'vertical roots' and 'horizontal roots', respectively. The 'vertical roots' especially those near rhizome, had superior tissue structure and physical characteristics compared with the 'horizontal roots'. The area of cross section of central cylinder and the number of vascular bundles largely contributed to the tensile strength of root. The area of cross section of cortex also contributed to the bending rigidity of root. The breaking force related to tensile strength and the second moment related to bending rigidity of the roots in edible canna were larger than those in other herbaceous plants, and these characteristics would be closely related to the high ability to support plants with a large aboveground mass.