Unveiling species diversity within early-diverging fungi from China XV: Three new species of Cunninghamellaceae (Mucorales)

Fungi in the family Cunninghamellaceae are widely distributed, with soil being their primary habitat. During the isolation and identification of fungi from soil samples collected in Guangdong and Yunnan Provinces, China, three new species of the genera Absidia and Cunninghamella were discovered, namely Absidia grisea sp. nov., A. dendroidea sp. nov., and Cunninghamella dimorpha sp. nov. Molecular phylogenetic analyses were performed using five loci: the internal transcribed spacer (ITS), large subunit (LSU), small subunit of ribosomal RNA gene (SSU rDNA), actin gene (ACT), and translation elongation factor 1 - alpha gene (TEF 1 α).

Absidia grisea is closely related to A. purpurea, and is distinguished by its gray colonies. Absidia dendroidea sp. nov. is closely related to A. stercoraria, and is characterized by up to seven dendroidal sporangiophores from a single point on stolons. In contrast, A. stercoraria produces a maximum of five sporangiophores arising from a single point on its stolons, a number distinctly lower than that of Absidia. dendroidea sp. nov.

Cunninghamella dimorpha forms a sister clade with C. blakesleeana, and differs mainly by producing two distinct spore morphologies. To date, with the addition of these three new species described in this paper, the total number of accepted species in the genera Absidia and Cunninghamella has increased to 82 and 48, respectively.