How important are conidial appendages?

Area of Science:

• Mycology
• Fungal Taxonomy
• Molecular Systematics

Background:

• Coelomycetous fungi classification relies on morphological features, including conidial appendages.
• The genus Dinemasporium serves as a model to assess the significance of these appendages in fungal taxonomy.
• Previous classifications may have overemphasized appendage morphology.

Purpose of the Study:

• To evaluate the importance of conidial appendages for generic-level classification of coelomycetous fungi.
• To revise the generic boundaries of Dinemasporium and related taxa.
• To introduce new species and genera based on integrated morphological and molecular data.

Main Methods:

• Morphological analysis of conidiomata, setae, conidia, and appendages.
• Molecular phylogenetic analysis using large subunit nuclear ribosomal RNA gene (LSU, 28S) and internal transcribed spacers (ITS) and 5.8S rRNA gene.
• Designation of epitypes for key species to stabilize nomenclature.

Main Results:

• The genus Dinemasporium is redefined, with five new species described: D. pseudostrigosum, D. americana, D. polygonum, D. pseudoindicum, and D. morbidum.
• A new genus, Brunneodinemasporium, is established for species with aggregated brown conidiogenous cells and pale brown conidia.
• Dendrophoma is reinstated as distinct from Dinemasporium, and Stauronema is synonymized under Dinemasporium. Pseudolachnea is confirmed as distinct.
• Appendage morphology alone was found to be uninformative at the generic level.

Conclusions:

• Conidial appendages are important but should be considered alongside other morphological and molecular characters for robust fungal classification.
• The study provides a revised taxonomic framework for the Dinemasporium generic complex.
• This work contributes to a more accurate understanding of coelomycetous fungal diversity and evolution.