Septoglomus deserticola emended and new combinations in the emended definition of the family Diversisporaceae

Abstract

An updated morphology of spores of <em>Septoglomus deserticola</em>, an arbuscular mycorrhizal fungus of the phylum Glomeromycota, is presented based on the original description of the species, only one other its definition recently published and spores produced in pot cultures inoculated with the rhizosphere soil and root fragments of an unrecognized grass colonizing maritime sand dunes of the Hicacos Peninsula, Cuba. Phylogenetic analyses of sequences of the large subunit (LSU) nrDNA region of the Cuban fungus confirmed its affinity with <em>S. deserticola </em>deposited in the International Bank for the Glomeromycota (BEG) and indicated that its closest relatives are <em>S. fuscum </em>and <em>S. xanthium</em>. Phylogenetic analyses of sequences of the small subunit (SSU) nrDNA confirmed the Cuban fungus x <em>S. fuscum </em>x <em>S. xanthium </em>relationship revealed in analyses of the LSU sequences and thereby suggested the Cuban <em>Septoglomus </em>is <em>S. deserticola</em>. However, it was impossible to prove directly the identity of the Cuban fungus and <em>S. deserticola </em>from BEG based on SSU sequences due to the lack of <em>S. deserticola </em>SSU sequences in public databases. In addition, phylogenetic analyses of LSU and SSU sequences confirmed the uniqueness of the recently erected genus <em>Corymbiglomus </em>with the type species <em>C. corymbiforme </em>(formerly <em>Glomus corymbiforme</em>) in the family Diversisporaceae and proved that its LSU sequences group in a clade with LSU sequences of <em>G. globiferum </em>and <em>G. tortuosum</em>. Consequently, the two latter species were transferred to <em>Corymbiglomus </em>and named <em>C. globiferum </em>comb. nov. and <em>C. tortuosum </em>comb. nov., and the definitions of the family Diversisporaceae and the genus <em>Diversispora </em>were emended.