Taxonomy and the evolutionary history of Micropeltidaceae

Taxonomy and evolution history of two new litter-decomposing Ciliochorella (Amphisphaeriales, Sporocadaceae)

The genus Ciliochorella is a group of pestalotioid fungi, which typically occurs in subtropical and tropical areas. Species from the Ciliochorella genus play important roles in the decomposition of litter. In this study, we introduce two new species (Ciliochorellachinensissp. nov. and C.savannicasp. nov.) that were found on leaf litter collected from savanna-like vegetation in hot dry valleys of southwestern China. Phylogenetic analyses of combined LSU, ITS and tub2 sequence datasets indicated that C.chinensis and C.savannica respectively form a distinct clade within the Ciliochorella genus. The comparison of the morphological characteristics indicated that the two new species are well differentiated within this genus species. Analysis of the evolutionary history suggests that Ciliochorella originated from the Eurasian continent during the Paleogene (38 Mya). Further, we find that both new species can produce cellulase and laccase, playing a decomposer role.

Exploring ascomycete diversity in Yunnan, China I: resolving ambiguous taxa in Phaeothecoidiellaceae and investigating conservation implications of fungi

Yunnan, located in southwestern China, is known for its high fungal diversity, and many of which are endemic to the region. As part of our ongoing studies on fungi in Yunnan, we introduce two new genera in Phaeothecoidiellaceae (Mycosphaerellales), to accommodate one Repetophragma-like and another Stomiopeltis-like taxa. Pseudorepetophragma gen. nov. is introduced herein as a monotypic genus to accommodate P. zygopetali comb. nov.(≡ Repetophragma zygopetali), whereas Pseudostomiopeltis gen. nov. is introduced to accommodate Ps. xishuangbannaensis gen. et sp. nov. and Ps. phyllanthi comb. nov.(≡ Stomiopeltis phyllanthi), based on a new collection from Yunnan. In addition, Stomiopeltis sinensis is transferred to Exopassalora as E. sinensis comb. nov. due to its phylogenetic affinity and grouped with E. zambiae, the generic type of Exopassalora. This study provides new insights into the biodiversity of fungal species in this region and adds to our understanding of their ecological roles, as well as the resolution to ambiguous taxa in Phaeothecoidiellaceae.

The first Gondwanan Euphorbiaceae fossils reset the biogeographic history of the Macaranga-Mallotus clade

PREMISE

The spurge family Euphorbiaceae is prominent in tropical rainforests worldwide, particularly in Asia. There is little consensus on the biogeographic origins of the family or its principal lineages. No confirmed spurge macrofossils have come from Gondwana.

METHODS

We describe the first Gondwanan macrofossils of Euphorbiaceae, represented by two infructescences and associated peltate leaves from the early Eocene (52 Myr ago [Ma]) Laguna del Hunco site in Chubut, Argentina.

RESULTS

The infructescences are panicles bearing tiny, pedicellate, spineless capsular fruits with two locules, two axile lenticular seeds, and two unbranched, plumose stigmas. The fossils' character combination only occurs today in some species of the Macaranga-Mallotus clade (MMC; Euphorbiaceae), a widespread Old-World understory group often thought to have tropical Asian origins. The associated leaves are consistent with extant Macaranga.

CONCLUSIONS

The new fossils are the oldest known for the MMC, demonstrating its Gondwanan history and marking its divergence by at least 52 Ma. This discovery makes an Asian origin of the MMC unlikely because immense oceanic distances separated Asia and South America 52 Ma. The only other MMC reproductive fossils so far known are also from the southern hemisphere (early Miocene, southern New Zealand), far from the Asian tropics. The MMC, along with many other Gondwanan survivors, most likely entered Asia during the Neogene Sahul-Sunda collision. Our discovery adds to a substantial series of well-dated, well-preserved fossils from one undersampled region, Patagonia, that have changed our understanding of plant biogeographic history.

Extending the fossil record for foliicolous Dothideomycetes: Bleximothyrium ostiolatum gen. et sp. nov., a unique fly-speck fungus from the Lower Cretaceous of Virginia, USA

PREMISE

Fossils can reveal long-vanished characters that inform inferences about the timing and patterns of diversification of living fungi. Through analyzing well-preserved fossil scutella, shield-like covers of fungal sporocarps, we describe a new taxon of early Dothideomycetes with a combination of characters unknown among extant taxa.

METHODS

Macerated clays from the Potomac Group, lower Zone 1, from the Lower Cretaceous (Aptian, 125-113 Ma) of Virginia USA yielded one gymnospermous leaf cuticle colonized by 21 sporocarps of a single fungal morphotype. We inferred a tree from nuclear ribosomal DNA of extant species, and coded morphological characters to evaluate alternative, equally parsimonious placements of the fossil in a molecular constraint tree of extant species.

RESULTS

Bleximothyrium ostiolatum gen. et sp. nov. has an ostiolate scutellum of radiate, dichotomizing hyphae. Unlike otherwise similar extant and fossil taxa, B. ostiolatum has tangled hyphae at its scutellum margin. Scutella of B. ostiolatum are connected to superficial mycelium, to intercalary and lateral appressoria, and to extensive subcuticular "mycélium en palmettes". The gymnospermous host has characters consistent with identity as a non-papillate ginkgophyte or cycad.

CONCLUSIONS

Bleximothyrium ostiolatum is the oldest known fossil fly-speck fungus that occurs on plant cuticles and has the radiate, ostiolate scutellum known only from Dothideomycetes. Its combination of characters, its scutellum margin, and mycélium en palmettes are unknown in other extant and fossil species, and Bleximothyrium ostiolatum likely represents a new group of fly-speck fungi that may now be extinct.

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.

The insights into the evolutionary history of Translucidithyrium: based on a newly-discovered species

During the field studies, a Translucidithyrium-like taxon was collected in Xishuangbanna of Yunnan Province, during an investigation into the diversity of microfungi in the southwest of China. Morphological observations and phylogenetic analysis of combined LSU and ITS sequences revealed that the new taxon is a member of the genus Translucidithyrium and it is distinct from other species. Therefore, Translucidithyrium chinensesp. nov. is introduced here. The Maximum Clade Credibility (MCC) tree from LSU rDNA of Translucidithyrium and related species indicated the divergence time of existing and new species of Translucidithyrium was crown age at 16 (4–33) Mya. Combining the estimated divergence time, paleoecology and plate tectonic movements with the corresponding geological time scale, we proposed a hypothesis that the speciation (estimated divergence time) of T. chinense was earlier than T. thailandicum. Our findings provided new insights into the species of Translucidithyrium about ecological adaptation and speciation in two separate areas.

Additions to Chaetothyriaceae (Chaetothyriales): Longihyalospora gen. nov. and Ceramothyrium longivolcaniforme, a new host record from decaying leaves of Ficus ampelas

A novel ascomycete genus, Longihyalospora, occurring on leaf litter of Ficus ampelas in Dahu Forest Area in Chiayi, Taiwan is described and illustrated. Longihyalospora is characterized by dark mycelium covering the upper leaf surface, elongate mycelial pellicle with ring of setae, pale brown to brown peridium, broadly obovoid, short pedicellate asci and hyaline, fusiform, elongated (tapering ends) and multi-septate ascospores with a thin mucilaginous sheath. Phylogenetic analyses of combined ITS, LSU and SSU sequence data revealed Longihyalospora as a distinct genus within the Chaetothyriaceae with high bootstrap support. Moreover, based on morphological similarities, Chaetothyrium vermisporum transferred to the new genus. In addition, Ceramothyrium longivolcaniforme is reported for the first time on Ficus ampelas. Newly added species are compared with other similar species and comprehensive descriptions and micrographs are provided.