Spore wall architecture of Glomus spp.

Abstract

Vesicular–arbuscular mycorrhizal fungal spore walls are of important diagnostic value in identifying a species within a genus. Since ultrastructural descriptions have so far been limited to a few species, the aim of this work was to describe the ultrastructural organization of seven species of Glomus. All these species show a different overall architecture, confirming wall analysis as a good taxonomic criterion. Some features, however, were shared by all spores, chiefly a fibrillar texture given by highly ordered fibrils embedded in an amorphous matrix; the rhythm of the fibrillar deposition seems to be specific for each species. The meaning of such ordered deposition is discussed.