Fungal Systematics and Evolution: FUSE 5

200 years of taxonomic confusion: Sporendonema and allies

The genus Sporendonema (Gymnoascaceae, Onygenales) was introduced in 1827 with the type species S. casei for a red mould on cheese. Cheese is a consistent niche for this species. Sphaerosporium equinum is another species classified in Gymnoascaceae and has also been reported from cheese. Recently, other habitats have been reported for both Sporendonema casei and Sphaerosporium equinum. The present study aimed to investigate the taxonomy of Sporendonema and Sphaerosporium, as well as a close neighbour, Arachniotus. Two strains of Hormiscium aurantiacum, another related cheese-associated species were also included in the analyses. Strains were evaluated in terms of macro- and micromorphology, physiology including salt tolerance, growth rate at different temperatures, casein degradation, cellulase activity, lipolytic activity, and multi-locus phylogeny with sequences of the nuclear ribosomal internal transcribed spacer region, the D1-D2 region of the large subunit and partial β-tubulin locus sequences. The results showed that the analysed species were congeneric, and the generic names Arachniotus and Sphaerosporium should be reduced to the synonymy of Sporendonema. Therefore, four new combinations as well as one lectotype and one epitype were designated in Sporendonema. Two strains attributed to Sphaerosporium equinum from substrates other than cheese were found to be phylogenetically and morphologically deviant and were introduced as a new species named Sporendonema isthmoides.

New species of Mallocybe (Agaricales, Inocybaceae) from Pakistan, based on morphological and molecular evidence

Within the family Inocybaceae, many species of Mallocybe have been reported, but there are only a few reports of this genus from Pakistan. In this study, six collections of Mallocybe were studied by morphological and phylogenetic methods. Phylogenetic analyses, based on sequence data from two different loci (ITS and LSU) using Maximum Likelihood and Maximum Parsimony methods, have been performed to infer species relationships within Mallocybe. Results indicated that these six collections encompass two new species of Mallocybe i.e. M.pakistanica and M.pinicola, from Pakistan. Their detailed morphological descriptions and illustrations are also provided. In addition, comparison with morphologically closely-related taxa is also discussed. Previously, only two species of this genus have been recorded from Pakistan and, with this addition, the total number of reported taxa of Mallocybe has been raised to four from Pakistan. A key to the described taxa of Mallocybe from Pakistan is also provided.

Notes on four species of Russula subgenus Heterophyllidiae (Russulaceae, Russulales) from southern China

Heterophyllidiae, one of the main subgenus of Russula (Russulaceae, Russulales), is both ecologically and economically important. Although many studies have focused on subgenus Heterophyllidiae in China, the diversity, taxonomy, and molecular phylogeny still remained incompletely understood. In the present study, two new species, R. discoidea and R. niveopicta, and two known taxa, R. xanthovirens and R. subatropurpurea, were described based on morphology and molecular phylogenetic analyses of ITS and 28S DNA sequences with new collections of subgenus Heterophyllidiae from southern China. Both morphological and phylogenetic analyses consistently confirmed that R. niveopicta and R. xanthovirens belong to the subsect. Virescentinae, R. discoidea and R. subatropurpurea come under subsect. Heterophyllae, and R. prasina is synonymized with R. xanthovirens.

Two new species of Phaeohelotium (Leotiomycetes: Helotiaceae) from Chile and their putative ectomycorrhizal status

Species of the genus Phaeohelotium (Leotiomycetes: Helotiaceae) are cup fungi that grow on decaying wood, leaves, litter, and directly on soil. Northern Hemisphere species are primarily found on litter and wood, whereas in the Southern Hemisphere the genus includes a mix of saprotrophs as well as taxa that grow on soil in association with ectomycorrhizal trees. The diversity of this genus has not been fully explored in southern South America. Here we describe two species from Chile, Phaeohelotium maiusaurantium sp. nov. and Ph. pallidum sp. nov., found on soil in Patagonian Nothofagaceae-dominated forests. We present macro- and micromorphological descriptions, illustrations, and molecular phylogenetic analyses. The two new species are placed in Phaeohelotium with high support in our 15-locus phylogeny as well as phylogenetic reconstructions based on the internal transcribed spacer (ITS) region of the nuclear ribosomal RNA gene. Our ITS phylogeny places both Ph. maiusaurantium and Ph. pallidum in a well-supported subclade that includes ectomycorrhizal root tip samples from Australasia. Similar species can be separated from these new taxa based on morphological characteristics, biogeography, substrate, and sequence data. In addition, two unnamed species from Chilean Nothofagaceae forests (Phaeohelotium sp. 1 and Phaeohelotium sp. 2) are documented from scant collections and sequence data and await description until more material becomes available. Citation: Grupe II AC, Smith ME, Weier A, Healy R, Caiafa MV, Pfister DH, Haelewaters D, Quandt CA (2022). Two new species of Phaeohelotium (Leotiomycetes: Helotiaceae) from Chile and their putative ectomycorrhizal status. Fungal Systematics and Evolution 10: 231-249. doi: 10.3114/fuse.2022.10.10.

Apple Endophytic fungi and their antagonism against apple scab disease

Endophytic fungi are microorganisms with the ability to colonize plants for the entire or at least a significant part of their life cycle asymptomatically, establishing a plant-fungus association. They play an important role in balancing ecosystems, as well as benefiting host through increasing plant growth, and protecting the host plants from abiotic and biotic stresses using various strategies. In the present study, endophytic fungi were isolated from wild and endemic apple cultivars, followed by characterizing their antifungal effect against Venturia inaequalis. To characterize the endophytic fungi, 417 fungal strains were separated from 210 healthy fruit, leaf, and branch samples collected from the north of Iran. Among the purified fungal isolates, 33 fungal genera were identified based on the morphological characteristics, of which 38 species were detected according to the morphological features and molecular data of ITS, tef-1α, and gapdh genomic regions (related to the genus). The results represented that most of the endophytic fungi belonged to Ascomycota (67.8%), 31.4% of isolates were mycelia sterilia, while the others were Basidiomycota (0.48%) and Mucoromycota (0.24%). Additionally, Alternaria, Cladosporium, and Nigrospora were determined as the dominant genera. The antifungal properties of the identified isolates were evaluated against V. inaequalis in vitro to determine the release of media-permeable metabolites, Volatile Organic Compounds (VOCs), chitinase, and cellulase as antifungal mechanisms, as well as producing phosphate solubilisation as growth-promoting effect. Based on the results of metabolite and VOC tests, the six isolates of Acremonium sclerotigenum GO13S1, Coniochaeta endophytica 55S2, Fusarium lateritium 61S2, Aureobasidium microstictum 7F2, Chaetomium globosum 2S1 and Ch. globosum 3 L2 were selected for greenhouse tests. Further, Co. endophytica 55S2 and F. lateritium 61S2 could solubilize inorganic phosphate. All isolates except Ch. globosum 3 L2 exhibited cellulase activity, while chitinase activity was observed in Ch. globosum 2S1, Ch. globosum 3 L2, and F. lateritium 61S2. Finally, Co. endophytica 55S2 and Ch. globosum 2S1 completely controlled the disease on the apple seedling leaves under greenhouse conditions.

Phylogenetic and ecological reevaluation of the order Onygenales

The order Onygenales is classified in the class Eurotiomycetes of the subphylum Pezizomycotina. Families in this order have classically been isolated from soil and dung, and two lineages contain causative agents of superficial, cutaneous and systemic infections in mammals. The ecology and habitat choices of the species are driven mainly by the keratin and cellulose degradation abilities. The present study aimed to investigate whether the ecological trends of the members of Onygenales can be interpreted in an evolutionary sense, linking phylogenetic parameters with habitat preferences, to achieve polyphasic definitions of the main taxonomic groups. Evolutionary processes were estimated by multiple gene genealogies and divergence time analysis. Previously described families, namely, Arthrodermataceae, Ajellomycetaceae, Ascosphaeraceae, Eremascaceae, Gymnoascaceae, Onygenaceae and Spiromastigoidaceae, were accepted in Onygenales, and two new families, Malbrancheaceae and Neogymnomycetaceae, were introduced. A number of species could not be assigned to any of the defined families. Our study provides a revised overview of the main lines of taxonomy of Onygenales, supported by multilocus analyses of ITS, LSU, TUB, TEF1, TEF3, RPB1, RPB2, and ribosomal protein 60S L10 (L1) (RP60S) sequences, combined with available data on ecology, physiology, morphology, and genomics.

Morphological and phylogenetic evidence for two new species of Russula subg. Heterophyllidia from Guangdong Province of China

Two new species of Russulasubg.Heterophyllidia from Guangdong Province of China were described and illustrated based on morphological characters, and their identity supported by molecular phylogeny. R.luofuensis is morphologically characterized by a grayish yellow to brownish orange pileus center with a purplish gray to grayish magenta margin, a surface that is cracked and broken into small golden-brown patches, subglobose to broadly ellipsoid basidiospores with warts fused in short or long chains and a suprapellis composed of hyphal extremities with inflated, ellipsoid or globose cells and attenuated terminal cell. R.subbubalina is distinguished by the blanched almond to dark salmon pileus that is cracked with age, subglobose to broadly ellipsoid basidiospores with wart fused in short or long chains and frequently connected by line connections, a suprapellis with hyphal ends composed of inflated or ellipsoid cells and attenuated terminal cell, and pileocystidia that are mainly clavate and sometimes with round or ellipsoid appendage. The phylogenetic analyses based on ITS-nrLSU-mtSSU-TEF1 dataset were performed using maximum likelihood and Bayesian analysis. In terms of morphological features and molecular data, the former species belongs to subsect. Virescentinae, whereas the latter comes under subsect. Heterophyllinae.

Biogeography and Ecology of Magnaporthales: A Case Study

The order Magnaporthales belongs to Sordariomycetes, Ascomycota. Magnaporthales includes five families, namely Ceratosphaeriaceae, Pseudohalonectriaceae, Ophioceraceae, Pyriculariaceae, and Magnaporthaceae. Most Magnaporthales members are found in Poaceae plants and other monocotyledonous herbaceous plants ubiquitously as plant pathogens or endophytic fungi, and some members are found in decaying wood or dead grass as saprophytic fungi. Therefore, studying the biogeography and ecology of Magnaporthales is of great significance. Here, we described the biodiversity of endophytic Magnaporthales fungi from Poaceae at three latitudes in China and conducted a meta-analysis of the geography and ecology of Magnaporthales worldwide. We found that Magnaporthales is a dominant order in the endophytic fungi of Poaceae. More than half of the endophytic Magnaporthales fungi have a taxonomically uncertain placement. Notably, few endophytic fungi are grouped in the clusters with known saprophytic or pathogenic Magnaporthales fungi, indicating that they may have saprophytic and parasitic differentiation in nutritional modes and lifestyles. The meta-analysis revealed that most species of Magnaporthales have characteristic geographical, host, and tissue specificity. The geographical distribution of the three most studied genera, namely Gaeumannomyces, Magnaporthiopsis, and Pyricularia, in Magnaporthales may depend on the distribution of their hosts. Therefore, studies on the endophytic fungal Magnaporthales from monocotyledonous plants, including Poaceae, in middle and low latitudes will deepen our understanding of the biogeography and ecology of Magnaporthales.

Cortinarius pakistanicus and C. pseudotorvus: two new species in oak forests in the Pakistan Himalayas

The genus of basidiomycetous fungi Cortinarius occurs worldwide, from subtropical to boreal latitudes. Although molecular systematics has triggered the study of these fungi in the Americas and Europe in the last two decades, there is still limited research on its diversity in large portions of the planet, such as the high mountain ranges of Asia. Several collections of Cortinarius were made during mycological field trips conducted between 2014 and 2018 in pure oak forests in the Pakistan Himalayas. An integrative framework combining morphological and phylogenetic data was employed for their study. As a result, the two species C.pakistanicus and C.pseudotorvus are here described as new to science. Detailed macro- and micro-morphological descriptions, including SEM images of spores, and a molecular phylogenetic reconstruction based on nrITS sequence data are provided and used to discriminate the new species from morphologically and phylogenetically close taxa. Whereas our phylogenetic tree inference gave unequivocal support for the inclusion of C.pseudotorvus within C.sect.Telamonia, the assignment of C.pakistanicus to any known sections remained elusive. These species likely establish ectomycorrhizal associations with trees in the genus Quercus, making this type of forest in the Pakistan Himalayas a promising focus for future research on the diversity of Cortinarius.

Community Structure of Arbuscular Mycorrhizal Fungi in Soils of Switchgrass Harvested for Bioenergy

Learning more about the biodiversity and composition of arbuscular mycorrhizal fungi (AMF) under alternative agricultural management scenarios may be important to the sustainable intensification of switchgrass grown as a bioenergy crop. Using PacBio single-molecule sequencing and taxonomic resolution to the level of amplicon sequence variant (ASV), we assessed the effects of nitrogen amendment on AMF associating with switchgrass and explored relationships between AMF and switchgrass yield across three sites of various productivities in Wisconsin. Nitrogen amendment had little effect on AMF diversity metrics or community composition. While AMF ASV diversity was not correlated with switchgrass yield, AMF family richness and switchgrass yield had a strong, positive relationship at one of our three sites. Each of our sites was dominated by unique ASVs of the species Paraglomus brasilianum, indicating regional segregation of AMF at the intraspecific level. Our molecular biodiversity survey identified putative core members of the switchgrass microbiome, as well as novel clades of AMF, especially in the order Paraglomerales and the genus Nanoglomus Furthermore, our phylogenies unite the cosmopolitan, soil-inhabiting clade deemed GS24 with Pervetustaceae, an enigmatic family prevalent in stressful environments. Future studies should isolate and characterize the novel genetic diversity found in switchgrass agroecosystems and explore the potential yield benefits of AMF richness.IMPORTANCE We assessed the different species of beneficial fungi living in agricultural fields of switchgrass, a large grass grown for biofuels, using high-resolution DNA sequencing. Contrary to our expectations, the fungi were not greatly affected by fertilization. However, we found a positive relationship between plant productivity and the number of families of beneficial fungi at one site. Furthermore, we sequenced many species that could not be identified with existing reference databases. One group of fungi was highlighted in an earlier study for being widely distributed but of unknown taxonomy. We discovered that this group belonged to a family called Pervetustaceae, which may benefit switchgrass in stressful environments. To produce higher-yielding switchgrass in a more sustainable manner, it could help to study these undescribed fungi and the ways in which they may contribute to greater switchgrass yield in the absence of fertilization.

New species of Pseudosperma (Agaricales, Inocybaceae) from Pakistan revealed by morphology and multi-locus phylogenetic reconstruction

During fungal surveys between 2012 and 2014 in pine-dominated forests of the western Himalayas in Pakistan, several collections of Pseudosperma (Agaricales, Inocybaceae) were made. These were documented, based on morphological and molecular data. During this work, three new species came to light, which are here formally described as Pseudospermabrunneoumbonatum, P.pinophilum and P.triacicularis. These species belong in the genus PseudospermafideMatheny et al. (2019) = Pseudosperma clade fideMatheny (2005) = Inocybe sect. Rimosaes.s.fideLarsson et al. (2009). Macro- and micro-morphological descriptions, illustrations and molecular phylogenetic reconstructions of the studied taxa are provided. The new species are differentiated from their close relatives by basidiospore size and colouration of basidiomata. Molecular phylogenetic relationships are inferred using ITS (ITS1–5.8S–ITS2), nrLSU and mtSSU sequence data. All three newly-described taxa likely share an ectomycorrhizal association with trees in the genus Pinus. In addition, five names are recombined in Inosperma, Mallocybe and Pseudosperma. These are Inospermavinaceobrunneum, Mallocybeerratum, Pseudospermaalboflavellum, Pseudospermafriabile and Pseudospermaneglectum.