Abstract Detail

Systematics

Hirooka, Yuuri [1], Tanney, Joey [2], Nguyen, Hai [3], Seifert, Keith [1].

A proposal for a new family in the Onygenales for the genus Spiromastix.

Fungi in the genus Spiromastix (presently Onygenaceae) are characterized by gymnothecia bearing thick-walled, scimitar-shaped to helical peridial appendages and oblate to globose ascospores that are pitted to punctuate. The genus now includes six species isolated from subtropical and tropical soil, all of them lacking known asexual stages. During our investigation of the fungal flora of house dust, four unknown malbranchea-like strains were isolated from samples collected in Australia, the Federated States of Micronesia, Mexico, and New Zealand. Phylogenies inferred from SSU+LSU and ITS sequences demonstrated that these isolates represented four new species of Spiromastix, supported by high Bayesian inference posterior probabilities.  Additionally, the Spiromastix clade was phylogenetically isolated and distant from other families in the Onygenales, including the Onygenaceae.  Species of Spiromastix are normally differentiated by the morphology of their sexual state.  Surprisingly, these four species did not exhibit a sexual state on the nine different media tested.  Given the absence of a sexual state, conidiophore branching pattern and arthroconidial dimensions were used as characters to distinguish among the new species.  Our assays for keratin degradation showed that these four new species lack keratinolytic activity, a consistent feature in Spiromastix. This further distinguishes the genus from the otherwise keratinolytic genera classified in the Onygenaceae.  Based on our morphological, physiological and phylogenetic results, we propose to classify Spiromastix in a new family.

1 - Agriculture and Agri-Food Canada, Biodiversity (Mycology), 960 Carling Avenue, Ottawa, ON, K1A 0C6, Canada
2 - Carleton University, 960 Carling Avenue, Ottawa, ON, K1S 5B6, Canada
3 - University of Ottawa, Biology, 960 Carling Avenue, Ottawa, ON, K1N 6N5, Canada

Keywords:
Taxonomy
A new family
Onygenaceae
Keratin degradation
Asexual state.

Presentation Type: Offered Paper - Paper
Session: 14
Location: Room 103 AB/Kellogg Hotel and Conference Center
Date: Wednesday, June 11th, 2014
Time: 10:30 AM
Number: 14001
Abstract ID:21
Candidate for Awards:None