New sporocarpic taxa in the phylum Glomeromycota: Sclerocarpum amazonicum gen. et sp. nov. in the family Glomeraceae (Glomerales) and Diversispora sporocarpia sp. nov. in the Diversisporaceae (Diversisporales)

Abstract

Of the nearly 300 species of the phylum Glomeromycota comprising arbuscular mycorrhizal fungi (AMF), only 24 were originally described to form glomoid spores in unorganized sporocarps with a peridium and a gleba, in which the spores are distributed randomly. However, the natural (molecular) phylogeny of most of these species remains unknown. We found unorganized sporocarps of two fungi-producing glomoid spores: one in the Amazonian forest in Brazil (tropical forest) and the second in a forest of Poland (temperate forest). The unique spore morphology of the two fungi suggested that they are undescribed species. Subsequent phylogenetic analyses of sequences of the small subunit-internal transcribed spacer-large subunit nrDNA region and the RPB1 gene confirmed this assumption and placed the Brazilian fungus in a separate clade at the rank of genus, very strongly divergent from its sister clade representing the genus Glomus sensu stricto in the family Glomeraceae (order Glomerales). The Polish fungus was accommodated in a sister clade to a clade grouping sequences of Diversispora epigaea, a fungus that also occasionally produces spores in sporocarps, belonging in the Diversisporaceae (Diversisporales). Consequently, the Brazilian fungus was here described as the new genus and new species Sclerocarpum gen. nov. and S. amazonicum sp. nov., respectively. The Polish fungus was described as D. sporocarpia sp. nov. In addition, the supposed reasons for the low representation of sporocarpic species in the Glomeromycota were discussed and the known distribution of sporocarp-producing Glomeromycota was outlined.

The Glomeromycota in the Neotropics

“…Survey types of studies for AMF with a strong taxonomic basis should be encouraged in the Neotropics considering that some biodiversity hotspots are found in this realm ( Myers et al, 2000 ) and new taxa have been discovered in the Neotropics in the last decade ( e.g. , Goto et al, 2012 ; Blaszkowski et al, 2013 ; Jobim et al, 2019 ). Moreover, investigation of the AMF community associated with native and economically important plants occurring in the Neotropics like Ilex paraguariensis and Araucaria angustifolia ( Moreira et al, 2007 ) might reveal new and unreported AMF species.…”

Grzyby podziemne Pienińskiego Parku Narodowego – nowe dane o różnorodności i rozmieszczeniu

“…There is little information available about the diversity and distribution of hypogeous fungi in the Pieniny Mts. Previously only eight species were reported from this area: Choiromyces meandriformis (lubelska 1953, as C. venosus), Elaphomyces asperulus (guMińska 1990), Rhizopogon roseolus (guMińska 1972), Hysterangium crassum (guMińska 1970, 1972, as H. separabile), Hysterangium stoloniferum (koMur et al 2019, Russula mattiroloana, R. candidissima (vidal et al 2019) and Diversispora sporocarpia (JobiM et al 2019).…”

New Glomeromycotan Taxa, Dominikia glomerocarpica sp. nov. and Epigeocarpum crypticum gen. nov. et sp. nov. From Brazil, and Silvaspora gen. nov. From New Caledonia

“…In the phylum Glomeromycota, the largest group is represented by species producing glomoid spores, which arise blastically at tips of cylindrical or funnel-shaped sporogenous hyphae, as spores of Glomus macrocarpum (see Supplementary Table 1 for species authors), the type species of Glomus and the Glomeromycota (Clements and Shear, 1931;Schüßler and Walker, 2010;Oehl et al, 2011). Of the 330 known species of the Glomeromycota, approximately 60 were originally described to form glomoid spores in epigeous or hypogeous unorganized glomerocarps, i.e., fruit bodies with randomly distributed spores inside them (Gerdemann and Trappe, 1974;Morton, 1988;Jobim et al, 2019). Importantly, of the glomerocarpic species, only seven (Diversispora epigaea, Funneliformis mosseae, Glomus arborense, G. macrocarpum, Glomus pallidum, Glomus tenerum, and Glomus warcupii) were managed to grow in culture, and only eight (D. epigaea, Diversispora sporocarpia, G. macrocarpum, Redeckera megalocarpa, Redeckera fulva, Redeckera pulvinata, Sclerocarpum amazonicum, and Sclerocystis sinuosa) were provided with molecular data (Jobim et al, 2019), which essentially makes this group of fungi ascribed to the Glomeromycota difficult to characterize and classify.…”

“…Of the 330 known species of the Glomeromycota, approximately 60 were originally described to form glomoid spores in epigeous or hypogeous unorganized glomerocarps, i.e., fruit bodies with randomly distributed spores inside them (Gerdemann and Trappe, 1974;Morton, 1988;Jobim et al, 2019). Importantly, of the glomerocarpic species, only seven (Diversispora epigaea, Funneliformis mosseae, Glomus arborense, G. macrocarpum, Glomus pallidum, Glomus tenerum, and Glomus warcupii) were managed to grow in culture, and only eight (D. epigaea, Diversispora sporocarpia, G. macrocarpum, Redeckera megalocarpa, Redeckera fulva, Redeckera pulvinata, Sclerocarpum amazonicum, and Sclerocystis sinuosa) were provided with molecular data (Jobim et al, 2019), which essentially makes this group of fungi ascribed to the Glomeromycota difficult to characterize and classify. Among many unorganized glomerocarps, previously found from our studies in the Brazilian Northeast, there were two whose glomoid spores first seemed to be identical in morphology to each another but differed from glomoid spores of described species of the Glomeromycota.…”