Morphological and phylogenetic analysis of the early-diverging lineage of Glomeromycota suggest two new genera and recombinations in Archaeosporales

The family Archaeosporaceae (Archaeosporales), an early-diverging lineage of Glomeromycota, is currently represented by a single genus, Archaeospora, with seven species described. During the analysis of pot cultures established for the maintenance of Glomeromycota isolates, an unanticipated fungus emerged as a contaminant. Morphological and phylogenetic analyses revealed this fungus as a new species, forming an autonomous genus-level clade within Archaeosporaceae, herein proposed as Antiquispora disseminans gen. et sp. nov.

Sequences for this species were obtained using the newly designed primer FULlongF in combination with FULR, both not Glomeromycota specific. Positive clones after transformation were then screened and selected using the Archaeosporaceae - specific reverse primer SpAll _ Archaeo _ R in combination with the vector sequencing primers. In addition, independent phylogenetic analysis using specimen-based sequences and eDNA supported the genus status of Archaeospora ecuadoriana and A. spainii, both with diagnostic morphological traits, leading to the establishment of the new genus Andinospora to accommodate Andinospora ecuadoriana comb. nov. and the genus status revalidation of Palaeospora with P. spainii.

Archaeospora remains to include A. trappei, A. europaea, A. schenckii, while A. myriocarpa and A. undulata require additional analysis. Environmental sequences from the EUKARYOME database also showed that most of the genus-level clades described in Archaeosporaceae have worldwide distribution and are populated by several potential new species.