Search Results (9)

In a survey of the mycobiota from the dung of herbivorous animals collected in natural areas in Spain, an Alternaria isolate was found. Morphological data and a multi-locus phylogenetic approach carried out through Maximum Likelihood and Bayesian Inference analyses with three gene markers (i.e., the internal transcribed spacer of rDNA, glyceraldehyde-3-phosphate dehydrogenase, and plasma membrane ATPase) revealed that it represents a novel Alternaria species in Chalastospora. Alternaria muriformis sp. nov. is described and illustrated here. It is closely related to Alternaria abundans, Alternaria armoraciae, and Alternaria breviramosa, but can be easily differentiated by its production of muriform conidia. Key morphological features of the members of the Chalastospora section are provided. Full article

The genus Alternaria is comprised of well-known plant pathogens causing various important diseases in plants, as well as being common allergens in animals and humans. Species of Alternaria can be found as saprobes associated with various dead plant materials. This research aims to enhance the taxonomy of saprobic species in the genus Alternaria found on grasses and herbaceous plants from Italy, based on multi-locus phylogenetic analyses of a concatenated ITS, LSU, SSU, tef1-α, rpb2, gapdh and Alt-a1 DNA sequence dataset combined with morphological characteristics. Multi-locus phylogenetic analyses demonstrated six novel species belonging to the genus Alternaria sect. Alternaria as: A. muriformispora sp. nov., A. obpyriconidia sp. nov., A. ovoidea sp. nov., A. pseudoinfectoria sp. nov., A. rostroconidia sp. nov. and A. torilis sp. nov. Detailed morphological descriptions, illustrations and an updated phylogenetic relationship of taxa in the genus Alternaria sect. Alternaria are provided herein. Full article

During our ongoing survey of dematiaceous hyphomycetes associated with dead branches in tropical forests, eight Acrodictys isolates were collected from Hainan, China. Morphology from the cultures and phylogeny based on partial small subunit (SSU), entire internal transcribed spacer regions with intervening 5.8S (ITS), partial large subunit (LSU) of rRNA gene, partial beta-tubulin (tub2), and partial RNA polymerase II second largest subunit (rpb2) genes were employed to identify these isolates. As a result, four new species, namely Acrodictys bawanglingensis sp. nov., A. diaoluoshanensis sp. nov., A. ellisii sp. nov., and A. pigmentosa sp. nov., are introduced. Illustrations and descriptions of the four taxa are provided, along with comparisons with closely related taxa in the genus. For facilitating relative studies, an updated key to all accepted species of this genus is also compiled. Full article

The genus Codinaea is a phialidic, dematiaceous hyphomycete known for its intriguing morphology and turbulent taxonomic history. This polyphasic study represents a new, comprehensive view on the taxonomy, systematics, and biogeography of Codinaea and its relatives. Phylogenetic analyses of three nuclear loci confirmed that Codinaea is polyphyletic. The generic concept was emended; it includes four morphotypes that contribute to its morphological complexity. Ancestral inference showed that the evolution of some traits is correlated and that these traits previously used to delimit taxa at the generic level occur in species that were shown to be congeneric. Five lineages of Codinaea-like fungi were recognized and introduced as new genera: Codinaeella, Nimesporella, Stilbochaeta, Tainosphaeriella, and Xyladelphia. Dual DNA barcoding facilitated identification at the species level. Codinaea and its segregates thrive on decaying plants, rarely occurring as endophytes or plant pathogens. Environmental ITS sequences indicate that they are common in bulk soil. The geographic distribution found using GlobalFungi database was consistent with known data. Most species are distributed in either the Holarctic realm or tropical geographic regions. The ancestral climatic zone was temperate, followed by transitions to the tropics; these fungi evolved primarily in Eurasia and Americas, with subsequent transitions to Africa and Australasia. Full article

Pleurotheciales is the largest order in Savoryellomycetidae with a large proportion of species known from freshwater habitats. In order to investigate the phylogenetic relationships of taxa within Pleurotheciales and contribute to their diversity, submerged wood was collected from freshwater habitats in China (Yunnan Province) and Thailand. Two dematiaceous, sporodochial hyphomycetes and one annulatascales-like ascomycete with unusual morphology as compared to extant ones were discovered. They were subjected to DNA-based phylogenetic analyses and the results revealed three distinct lineages in Savoryellomycetidae. This morpho-phylo taxonomic study supports the establishment of five novel taxa including two novel genera, Obliquifusoideum and Saprodesmium, and three novel species, Coleodictyospora muriformis, Obliquifusoideum guttulatum and Saprodesmium dematiosporum. Coleodictyospora muriformis and S. dematiosporum are placed in Pleurotheciales, while O. guttulatum is referred to Savoryellomycetidae genera incertae sedis. The phylogenetic relationships are also presented for Coleodictyospora and Pseudocoleodictyospora, which raises an intriguing taxonomic issue. These two genera are positioned in two different classes, viz Sordariomycetes and Dothideomycetes, although they are quite similar except for the presence of a conidial sheath. This study expands our knowledge of the fungal diversity of freshwater fungi, and also indicates that Pleurotheciales species are mostly found in freshwater habitats. Full article

Zanclospora (Chaetosphaeriaceae) is a neglected, phialidic dematiaceous hyphomycete with striking phenotypic heterogeneity among its species. Little is known about its global biogeography due to its extreme scarcity and lack of records verified by molecular data. Phylogenetic analyses of six nuclear loci, supported by phenotypic data, revealed Zanclospora as highly polyphyletic, with species distributed among three distantly related lineages in Sordariomycetes. Zanclospora is a pleomorphic genus with multiple anamorphic stages, of which phaeostalagmus-like and stanjehughesia-like are newly discovered. The associated teleomorphs were previously classified in Chaetosphaeria. The generic concept is emended, and 17 species are accepted, 12 of which have been verified with DNA sequence data. Zanclospora thrives on decaying plant matter, but it also occurs in soil or as root endophytes. Its global diversity is inferred from metabarcoding data and published records based on field observations. Phylogenies of the environmental ITS1 and ITS2 sequences derived from soil, dead wood and root samples revealed seven and 15 phylotypes. The field records verified by DNA data indicate two main diversity centres in Australasia and Caribbean/Central America. In addition, environmental ITS data have shown that Southeast Asia represents a third hotspot of Zanclospora diversity. Our data confirm that Zanclospora is a rare genus. Full article

European ash (Fraxinus excelsior) is threatened by the invasive ascomycete Hymenoscyphus fraxineus originating from Asia. Ash leaf tissues serve as a route for shoot infection but also as a sporulation substrate for this pathogen. Knowledge of the leaf niche partitioning by indigenous fungi and H. fraxineus is needed to understand the fungal community receptiveness to the invasion. We subjected DNA extracted from unwashed and washed leaflets of healthy and diseased European ash to PacBio sequencing of the fungal ITS1-5.8S-ITS2 rDNA region. Leaflets from co-inhabiting rowan trees (Sorbus aucuparia) served as a reference. The overlap in leaflet mycobiomes between ash and rowan was remarkably high, but unlike in rowan, in ash leaflets the sequence read proportion, and the qPCR-based DNA amount estimates of H. fraxineus increased vigorously towards autumn, concomitant with a significant decline in overall fungal richness. The niche of ash and rowan leaves was dominated by epiphytic propagules (Vishniacozyma yeasts, the dimorphic fungus Aureobasidion pullulans and the dematiaceous hyphomycete Cladosporium ramotenellum and H. fraxineus), and endophytic thalli of biotrophs (Phyllactinia and Taphrina species), the indigenous necrotroph Venturia fraxini and H. fraxineus. Mycobiome comparison between healthy and symptomatic European ash leaflets revealed no significant differences in relative abundance of H. fraxineus, but A. pullulans was more prevalent in symptomatic trees. The impacts of host specificity, spatiotemporal niche partitioning, species carbon utilization profiles and life cycle traits are discussed to understand the ecological success of H. fraxineus in Europe. Further, the inherent limitations of different experimental approaches in the profiling of foliicolous fungi are addressed. Full article

In a survey of microfungi from plant debris collected in Vietnam, two new hyphomycetous species were found, which belong to the genera Heliocephala and Pseudopenidiella and the family Microthyriaceae (Microthyriales, Dothideomycetes). Maximum Likelihood and Bayesian Inference sequence analyses of the internal transcribed spacers (ITS) and large subunit (LSU) of the ribosomal DNA barcodes allowed assessing the phylogenetic relationships of the new species with other species of the respective genera. Heliocephala variabilis sp. nov. was closely related to Heliocephala elegans, Heliocephala gracilis, and Heliocephala zimbabweensis, from which it was morphologically distinguished by its smaller conidiophores and non-rostrate conidia of up to four septa on the natural substratum. Pseudopenidiella vietnamensis sp. nov. was related to Pseudopenidiella piceae and Pseudopenidiella podocarpi and differed from the former principally by its lack of microcondiophores and from P. podocarpi by having larger macroconidiophores and smooth conidia. Key morphological features to distinguish the accepted species in Heliocephala and Pseudopenidiella are also provided. In addition, Pseudopenidiella pini was excluded from the genus on the basis of its morphological features. Full article

Stemphylium blight (SB) caused by Ascomycete, Stemphylium botryosum Wallr. has been a serious threat to lentil cultivation, mainly in Bangladesh, Nepal, India, and Canada since its first outbreak in Bangladesh in 1986. The genus Stemphylium Wallr., a dematiaceous hyphomycete, comprises up to 150 species, and is pathogenic on a wide range of plants infecting leguminous as well as nonleguminous crops. In recent years, studies indicated overlapping in morphological characters among the different species under the genus Stemphylium, making the identification and description of species difficult. This necessitates different molecular phylogenetic analysis in species delimitation. Therefore, a detailed understanding of spatial diversity and population structure of the pathogen is pertinent for producing source material for resistance breeding. The role of different weather variables as predisposing factors for the rapid spread of the pathogen necessitates devising a disease predictive model for the judicial application of fungicides. A dearth of information regarding spore biology, epidemiology, race diversity, host-pathogen interaction, and holistic disease management approach necessitates immediate attention towards more intensive research efforts. This is the first comprehensive review on the current state of knowledge and research efforts being made for a better understanding of the SB resistance through cognizing biology, ecology, and epidemiology of S. botryosum and effective disease management strategies to prevent widespread outbreaks of SB. The information regarding the biology and epidemiology of S. botryosum is also crucial for strengthening the “Integrated Disease Management” (IDM) programme. The need for a regional research network is advocated where the disease is becoming endemic. Full article