Phylogenetic and phylogenomic analyses reveal two new genera and three new species of ophiostomatalean fungi from termite fungus combs

ABSTRACT

The Ophiostomatales (Ascomycota) accommodates more than 300 species characterized by similar morphological adaptations to arthropod dispersal. Most species in this order are wood-inhabiting fungi associated with bark or ambrosia beetles. However, a smaller group of species occur in other niches such as in soil and Protea infructescences. Recent surveys of Termitomyces fungus gardens (fungus combs) of fungus-growing termites led to the discovery of characteristic ophiostomatalean-like fruiting structures. In this study, these ophiostomatalean-like fungi were identified using morphological characteristics, conventional molecular markers, and whole genome sequencing. In addition, the influence of the extracts derived from various parts of Termitomyces combs on the growth of these fungi in culture was considered. Based on phylogenomic analyses, two new genera (Intubia and Chrysosphaeria) were introduced to accommodate these ophiostomatalean species. Phylogenetic analyses revealed that the isolates resided in three well-supported lineages, and these were described as three new species (Intubia macrotermitinarum, I. oerlemansii, and Chrysosphaeria jan-nelii). Culture-based studies showed that these species do not depend on the Termitomyces comb material for growth.

KEYWORDS:

• Fungus-growing termites
• Insect associated fungi
• Ophiostomataceae
• Termitomyces
• 5 new taxa

ACKNOWLEDGMENTS

We thank Dr. Seonju Marincowitz for assistance with microscopy.

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Additional information

Funding

This project was funded by The National Research foundation of South Africa (NRF), The University of Pretoria, the Tree Protection Co-operative Programme (TPCP), and Department of Science and Innovation (DSI)-NRF Centre of Excellence in Plant-Health Biotechnology (CPHB), and the DSI-NRF South African Research Chairs Initiative Chair for Fungal Genomics.