Isolation of <i>Frankia</i> from nodules of <i>Trevoa trinervis</i>: ultrastructural characterization

Abstract

Root nodules obtained from Trevoa trinervis and its actinomycete Frankia were studied by electron microscopy. The microsymbiont was found in the cortical cells and it exhibits the typical actinomycetal structures: septate hyphae and symbiotic vesicles. Using the double-layer technique, two Frankia strains were isolated from the nodules. In vitro these strains exhibit morphological characteristics considered specific to the genus Frankia, i.e., hyphae, Frankia vesicles, and polymorphic sporangia. Key words: Frankia, actinomycetes, Trevoa.