Systematics and taxonomy of Marthamycetales (Fungi, Ascomycota): Toward a revision of Propolis and Mellitiosporium

Marthamycetales (Fungi, Ascomycota, Leotiomycetes) species are common and widely distributed across the globe. They are associated with various woody plants and grasses. A few taxa are pathogenic, but most are presumed to be saprobic. Species of Marthamycetales produce small, erumpent apothecia on bark, wood, pinecones, and leaves. Apothecia are morphologically distinguished by their farinose discs that are encircled by ragged, projecting flaps of degraded plant tissue. The order currently circumscribes nine genera: Cyclaneusma, Marthamyces, Mellitiosporiella, Mellitiosporium, Naemacyclus, Phragmiticola, Propolina, Propolis, and Ramomarthamyces. The typification of Mellitiosporiella, Mellitiosporium, Propolina and Propolis has never been addressed, and modern descriptions of species are lacking. Furthermore, taxon sampling in gene-based phylogenetic analyses has been limited, with the result that the circumscription of the order and evolutionary relationships among taxa remains unclear. To begin a revision of these genera, the nomenclature and taxonomy of types was undertaken. A proposal to conserve the type of Propolis, P. farinosa, was submitted for review by the Nomenclature Committee for Fungi. A second proposal was submitted to conserve the orthography of Mellitiosporiella and Mellitiosporium, as well as to conserve the type of Mellitiosporium. Archive and fungarium research was conducted to clarify the circumscription of P. farinosa, under which several names have long been synonymized based on literature research rather than critical study of type material. A revised circumscription of Marthamycetales was produced based on morphology of type specimens as well as a multi-gene phylogenetic analysis using nSSU, nITS, nLSU, and mtSSU loci and analyzed using maximum likelihood and Bayesian approaches. Sampling of the types of all genera was accomplished. A separate nITS-only phylogenetic analysis was conducted for Phragmiticola phragmitis. Ramomarthamyces octomerus was described because it is morphologically distinctive within this genus and in Marthamycetales. The results of the nITS analysis of Phragmiticola supported the exclusion of this genus from Marthamycetales and its placement in Helotiales, Arachnopezizaceae. In the Marthamycetales phylogenetic analysis, an isolate of the previously unsequenced Cryptomyces pteridis was used as an additional outgroup taxon; this was estimated to be a member of Leotiomycetes, although unplaced in any order. The phylogenetic analysis of the remaining Marthamycetales species estimated two well-supported clades that could be broadly characterized by morphological and ecological features: one clade encompassed primarily filiform-spored, leaf inhabiting species in Marthamycetaceae sensu stricto (Cyclaneusma, Marthamyces, Naemacyclus, Ramomarthamyces); the second clade encompassed primarily cylindrical/elliptical-spored, woody tissue inhabiting species that we place in Propoliaceae fam. nov. (Mellitiosporiella, Mellitiosporium, Propolina, Propolis). Surprisingly, the conidial, helical-spored fungus Everhartia hymenuloides, type of the genus, clustered within the Propoliaceae clade, sister to Propolis, and is included in Propoliaceae as incertae sedis. In addition to these results, Propolina clusters within in a well-supported Propolis clade and is here placed in synonymy under Propolis. A new combination for the type, Propolis cervina, is proposed. An updated and expanded description of Marthamycetales is provided, along with diagnoses of Marthamycetaceae and Propoliaceae fam. nov. An overview of mitosporic states in Marthamycetales is included. Lectotypes are designated for Stictis alba and Tremella saligna. Original material of Hysterium fagineum, Propolina cervina, Propolis versicolor var. luteola, Pseudographis phragmitis, and Stictis cinerascens are described for the purposes of lectotypification and neotypification in future publications.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Plant Biology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2024

Author dc:creator

• Karakehian, Jason Michael

Contributors dc:contributor

• Miller, Andrew N
• Dalling, James W
• Pfister, Donald H
• Downie, Stephen R

• Fungi
• Leotiomycetes

Statement dc:rights

• Copyright 2024 Jason Karakehian

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/127474

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F127474