Valsaria and the Valsariales

Refined families of Dothideomycetes: orders and families incertae sedis in Dothideomycetes

Numerous new taxa and classifications of Dothideomycetes have been published following the last monograph of families of Dothideomycetes in 2013. A recent publication by Honsanan et al. in 2020 expanded information of families in Dothideomycetidae and Pleosporomycetidae with modern classifications. In this paper, we provide a refined updated document on orders and families incertae sedis of Dothideomycetes. Each family is provided with an updated description, notes, including figures to represent the morphology, a list of accepted genera, and economic and ecological significances. We also provide phylogenetic trees for each order. In this study, 31 orders which consist 50 families are assigned as orders incertae sedis in Dothideomycetes, and 41 families are treated as families incertae sedis due to lack of molecular or morphological evidence. The new order, Catinellales, and four new families, Catinellaceae, Morenoinaceae Neobuelliellaceae and Thyrinulaceae are introduced. Seven genera (Neobuelliella, Pseudomicrothyrium, Flagellostrigula, Swinscowia, Macroconstrictolumina, Pseudobogoriella, and Schummia) are introduced. Seven new species (Acrospermum urticae, Bogoriella complexoluminata, Dothiorella ostryae, Dyfrolomyces distoseptatus, Macroconstrictolumina megalateralis, Patellaria microspora, and Pseudomicrothyrium thailandicum) are introduced base on morphology and phylogeny, together with two new records/reports and five new collections from different families. Ninety new combinations are also provided in this paper.

Evolution of lifestyles in Capnodiales

The Capnodiales, which includes fungi known as the sooty moulds, represents the second largest order in Dothideomycetes, encompassing morphologically and ecologically diverse fungi with different lifestyles and modes of nutrition. They include saprobes, plant and human pathogens, mycoparasites, rock-inhabiting fungi (RIF), lichenised, epi-, ecto- and endophytes. The aim of this study was to elucidate the lifestyles and evolutionary patterns of the Capnodiales as well as to reconsider their phylogeny by including numerous new collections of sooty moulds, and using four nuclear loci, LSU, ITS, TEF-1α and RPB2. Based on the phylogenetic results, combined with morphology and ecology, Capnodiales s. lat. is shown to be polyphyletic, representing seven different orders. The sooty moulds are restricted to Capnodiales s. str., while Mycosphaerellales is resurrected, and five new orders including Cladosporiales, Comminutisporales, Neophaeothecales, Phaeothecales and Racodiales are introduced. Four families, three genera, 21 species and five combinations are introduced as new. Furthermore, ancestral reconstruction analysis revealed that the saprobic lifestyle is a primitive state in Capnodiales s. lat., and that several transitions have occurred to evolve lichenised, plant and human parasitic, ectophytic (sooty blotch and flyspeck) and more recently epiphytic (sooty mould) lifestyles.

Multigene phylogenetic analyses to establish new Valsaria species and taxonomic significance of spore ornamentation

During our studies on fungal diversity from plant substrates, a new species of Valsaria was isolated from dead branches of Ostrya carpinifolia. The taxon is morphologically similar to other taxa in Valsariaceae and is characterized by pseudostromata, apically free pseudoparaphyses, bitunicate asci, and dark brown, 2-celled ascospores. However, it differs from extant species in number of guttules and ornamentation of spore. It is introduced herein as Valsaria ostryae sp. nov. within the family Valsariaceae. Multigene phylogenies based on combined LSU, ITS and RPB2 DNA sequence data generated from maximum likelihood, maximum parsimony and MrBayes analyses indicate that V. ostryae is basal to V. lopadostomoides and V. rudis and its establishment as a new species is strongly supported. No discordance was found between our morphological and phylogenetic species boundaries as postulated by other researchers and our molecular data strongly supports ornamentation of spore as useful for species delineation. Valsaria species do not appear to be host specific. Full morphological details are provided herein and phylogenetic relationships of Valsaria species are also discussed in light with host association.

Taxonomy and phylogeny of Laburnicola gen. nov. and Paramassariosphaeria gen. nov. (Didymosphaeriaceae, Massarineae, Pleosporales)

Laburnicola gen. nov., with four new species, Paramassariosphaeria gen. nov., with a new species and Montagnula saikhuensis sp. nov. are introduced in this paper. The phylogeny of these taxa and genera of Didymosphaeriaceae are resolved based on analysis of combined LSU, SSU, and ITS sequence data. Laburnicola is characterized by obpyriform, immersed ascomata, with a peridium fused to the host tissues, long pedicellate asci and ellipsoidal to fusoid ascospores, whose central cells have longitudinal septa and a rugged surface. Paramassariosphaeria is characterized by globose to subglobose ascomata, papillate ostioles, a peridium comprising pseudoparenchymatous cells of textura angularis, cylindric-clavate to clavate, pedicellate asci and brown, curved-fusoid ascospores, with multiple transverse septa and a mucilaginous sheath. Montagnula saikhuensis has immersed ascomata, with a peridium fused to the host tissues, long pedicellate asci and blackish brown, ellipsoidal ascospores with a single septum. The relationship of these taxa with other Didymosphaeriaceae species is discussed based on comparative morphology and phylogenetic analysis. Munkovalsaria appendiculata and Munkovalsaria donacina are transferred to the genus Montagnula.

Hidden diversity in Thyridaria and a new circumscription of the Thyridariaceae

A multigene analysis of a combined ITS-LSU-SSU-rpb2-tef1 sequence data matrix was applied to infer the phylogenetic position of the genus Thyridaria in the Pleosporales. The generic type of Thyridaria, T. broussonetiae (syn. T. incrustans), is situated in a clade currently named Roussoellaceae, which becomes a synonym of Thyridariaceae. However, Thyridaria rubronotata does not belong to this clade, but is here recognised as Cyclothyriella rubronotata in its own family Cyclothyriellaceae. The Thyridariaceae contain the genera Thyridaria, Roussoella, Roussoellopsis, Neoroussoella and the new genus Parathyridaria. Roussoella acaciae is combined in Thyridaria and Roussoella percutaenea in Parathyridaria. Ohleria modesta and an additional new thyridaria-like genus, Hobus, are found to represent isolated lineages with unresolved phylogenetic affinites within the Pleosporales. For Ohleria the new family Ohleriaceae is established. Melanomma fuscidulum belongs to Nigrograna, and three new species are described in this genus. A strain named Biatriospora marina clusters with Nigrograna. Based on the newly recognised species in Nigrograna, morphology and ecology do in no way correlate among these genera, therefore we erect the new family Nigrogranaceae for Nigrograna and recommend to discontinue the use of the family name Biatriosporaceae until fresh material of B. marina becomes available for sequencing.

Reassessment of Allantonectria, phylogenetic position of Thyronectroidea, and Thyronectria caraganae sp. nov

The genus Allantonectria is synonymised with Thyronectria, based on morphological and molecular phylogenetic considerations. Investigations of types and fresh collections revealed that Tubercularia concentrica is an earlier name for Sphaeria (syn. Allantonectria) miltina and is thus combined in Thyronectria. Allantonectria yuccae is recognised as a distinct species and transferred to Thyronectria, as well as the recently described A. zangii. Descriptions and illustrations are provided for T. concentrica and T. yuccae. A recent collection of the North American Thyronectroidea chrysogramma, the generic type of Thyronectroidea, was studied with respect to morphology of its sexual morph in fresh condition and of its asexual morph produced in pure culture. Molecular phylogenies based on six loci (ITS and LSU regions of nuc rDNA, act1, rpb1, rpb2, tef1 and tub2 genes) place T. chrysogramma within Thyronectria, confirming synonymy of Thyronectroidea with Thyronectria, but remarkably a relationship to European species with green to brown spores (former genus Mattirolia) receives no support, and its closest relatives remain unclear. Thyronectria caraganae is described as a new species from herbarium specimens of Caragana arborescens collected in the Ukraine. It is characterised by morphology of the sexual morph and by DNA sequence data, which place it within the T. austroamericana - T. rhodochlora clade with high support. This is also supported by its morphology, specifically ascomata partly embedded within a stroma, muriform ascospores not budding within the ascus, becoming yellowish to rosy at maturity.

Teichospora and the Teichosporaceae

A multigene analysis of a combined ITS, LSU, SSU, rpb2 and tef1 sequence data matrix was applied to infer the phylogenetic position of the genus Teichospora in the Pleosporales, based on isolates from freshly collected material of the generic type T. trabicola and several additional species. Phylogenetic analyses revealed that Misturatosphaeria and Floricola are synonyms of Teichospora. All species of these genera and several species recently described in the genus Curreya belong to Teichospora and are thus combined in this genus. Also, Melanomma radicans and Ramusculicola thailandica are combined in Teichospora. The new name Teichospora parva is established for Misturatosphaeria minima. Three new species, T. melanommoides, T. pusilla and T. rubriostiolata, are described, and an expanded description of T. mariae is given. The family Teichosporaceae is currently confined to Teichospora, which can be phylogenetically clearly separated from Lophiostoma, the type genus of the Lophiostomataceae. The family name Floricolaceae is a synonym of Teichosporaceae. All species described here form apically free paraphyses among immature asci. This finding contradicts the current general dogma that apically free paraphyses are absent in the Pleosporales and questions the wide use of the term pseudoparaphysis.

Asterodiscus and Stigmatodiscus, two new apothecial dothideomycete genera and the new order Stigmatodiscales

During a survey on corticolous Dothideomycetes, several collections with ascospores matching the genera Asteromassaria and Stigmatomassaria (Pleomassariaceae, Pleosporales) were revealed from dead corticated twigs of Acer, Carpinus and Tamarix. Closer morphological examination showed that their ascomata were apothecial, with a hamathecium consisting of septate, branched paraphyses, which are apically swollen at maturity. Several collections were cultured and sequenced, and a Blast search of their nuc 28S rDNA sequences revealed dothideomycetous affiliation, but without a close match to a specific family or order. Phylogenetic analyses of a multigene matrix containing a representative selection of Dothideomycetes from four genes (nuc 18S rDNA, nuc 28S rDNA, rpb2 and tef1) revealed placement within Dothideomycetes but without a supported familial or ordinal affiliation. Based on the phylogenetic analyses and morphological investigations, the new genera Asterodiscus and Stigmatodiscus, with the two new species A. tamaricis and S. enigmaticus, are described and illustrated, and placed in the new family Stigmatodiscaceae and new order Stigmatodiscales.