Morphogenesis of Roots in Edible Canna. With special reference to adventitious roots.

Abstract

The morphological and anatomical features of the development of roots in edible canna (Canna edulis Ker-Gawl.) were investigated with special reference to its adventitious roots. A typical fibrous root system, which was comprised of thick adventitious roots and thinner primary and secondary lateral roots, was formed in this species. In mature adventitious roots, the polyarch stele with many vessels and the cortex with lacunae were unique features. There was no clear nodal structure in the stele of rhizome and the intimate interconnection of node and stelar vascular bundle was not observed. There was no regularity of the development of adventitious roots as seen in gramineous species. Compared with Musa species, the morphological and anatomical features were rather similar but the number of primordia and thickness of adventitious roots, the number of vascular bundles, and the size of lacunae were smaller in edible canna. It is considered that the mode of development and tissue structure of adventitious roots are related to the morphogenesis of the root system to support the large aboveground part of this species.