Glomus perpusillum, a new arbuscular mycorrhizal fungus

Abstract

A new arbuscular mycorrhizal fungal species of genus Glomus, G. perpusillum (Glomeromycota), forming small, hyaline spores is described and illustrated. Spores of G. perpusillum were formed in hypogeous aggregates and occasionally inside roots. They are globose to subglobose, (10-)24(-30) microm diam, rarely egg-shaped, oblong to irregular, 18-25 x 25-63 microm. The single spore wall of G. perpusillum consists of two permanent layers: a finely laminate, semiflexible to rigid outer layer and a flexible to semiflexible inner layer. The inner layer becomes plastic and frequently contracts in spores crushed in PVLG-based mountants and stains reddish white to grayish red in Melzer's reagent. Glomus perpusillum was associated with roots of Ammophila arenaria colonizing sand dunes of the Mediterranean Sea adjacent to Calambrone, Italy, and this is the only site of its occurrence known to date. In single-species cultures with Plantago lanceolata as host plant, G. perpusillum formed vesicular-arbuscular mycorrhiza. Phylogenetic analyses of partial SSU sequences of nrDNA placed the species in Glomus group A with no affinity to its subgroups. The sequences of G. perpusillum unambiguously separated from the sequences of described Glomus species and formed a distinct clade together with in planta arbuscular mycorrhizal fungal sequences found in alpine plants.

Mantled fungal reproductive units in land plant tissue from the Lower Devonian Rhynie chert

“…in which spore size is similar to that of the fossils [e.g., (10-)24(-30) µm in Glomus perpusillum Błaszk. & Kovács and (17-)32(-52) µm in Glomus indicum Błaszk., Wubet & Harikumar; see Błaszkowski et al 2009Błaszkowski et al , 2010. Certain species in the zygomycete genus Mortierella Coem.…”

Where is the unseen fungal diversity hidden? A study of Mortierella reveals a large contribution of reference collections to the identification of fungal environmental sequences

“…Of course, we in no way intend to deny the presence of novel lineages or the ability of Sanger-based and nextgeneration sequencing techniques used in environmental studies to recover them. Two examples are given, among others, by Blaszkowski et al (2009) and Jacobsson & Larsson (2009), where the species were first detected in environmental samples and their sequences were then matched to sequences from voucher specimens after they had been described formally. Certainly, there are thousands of new species awaiting description, but our results suggest that the importance of herbarium voucher specimens should also be emphasized.…”

Arbuscular mycorrhizal fungi (Glomeromycota) associated with roots of plants

“…observ.). on the other hand, cultivation of field soils in trap cultures may initiate sporulation of fungi forming spores seasonally, rarely or not at all in field conditions (Błaszkowski, Kovács and Balázs 2009;Błaszkowski, Tadych and madej 2000;Stutz, morton 1996). an ideal method of recognizing of amF associated with plant roots seems to be that using molecular tools.…”