Κυριακή 17 Νοεμβρίου 2019

Pseudoplagiostoma myracrodruonis (Pseudoplagiostomataceae, Diaporthales): a new endophytic species from Brazil

Abstract

Two initially unidentifiable isolates were found when endophytic fungi from healthy leaves of Myracrodruon urundeuva (Anacardiaceae) were being investigated in Brazil. Based on phylogenetic analyses using internal transcribed spacer (ITS) and partial large subunit (LSU) of ribosomal DNA, RNA polymerase II (RPB2), translation elongation factor EF-1 alpha (TEF1), and tubulin (TUB2), the isolates were identified as members of the family Pseudoplagiostomataceae (Diaporthales). In this paper, we introduce a new species, Pseudoplagiostoma myracrodruonis, thus accepting eight species in Pseudoplagiostoma (Pseudoplagiostomataceae). The new species is proposed to accommodate endophytes characterized by a coelomycetous asexual morph, pycnidial conidiomata with lageniform to ampulliform and hyaline to pale brown phialidic conidiogenous cells that produce unicellular, ellipsoid to oblong-cylindrical, hyaline, and guttulate conidia. In the current phylogenetic analysis, Pmyracrodruonis is placed in a well-supported clade in Pseudoplagiostoma (Pseudoplagiostomataceae). A discussion about the relationship of Pseudoplagiostoma species is included in the paper.

Morphological characters and molecular data reveal three new species of Fomitopsis (Basidiomycota)

Abstract

Fomitopsis is an important, cosmopolitan brown-rot genus. Recent phylogenetic analyses showed that Fomitopsis was polyphyletic. During the taxonomic studies of Fomitopsis, three new species were discovered. Phylogenetic analyses carried out based on sequences from the internal transcribed spacer (ITS) regions, the large subunit of nuclear ribosomal RNA gene (nLSU), the small subunit of nuclear ribosomal RNA gene (nSSU), the small subunit of mitochondrial rRNA gene (mtSSU), the second largest subunit of RNA polymerase II (RPB2), and the translation elongation factor 1-α gene (TEF), confirmed the affinities of three new species within Fomitopsis sensu stricto. Fomitopsis caribensis sp. nov. was discovered from Puerto Rico and is characterized by pileate, fragile basidiomata, becoming hard corky upon drying, a white to cream pore surface when fresh, pinkish buff when dry, round to angular and small pores (6–9 per mm), and cylindrical to oblong-ellipsoid basidiospores (6–7.5 × 2.3–3.1 μm). Fomitopsis eucalypticola sp. nov. was collected from Australia. It is characterized by effused-reflexed to pileate basidiomata, cream to salmon pileal surface, cream to yellow pore surface when fresh, becoming buff to clay-buff when dry, occasionally simple-septate skeletal hyphae, long cystidioles (15–36 × 2–5.3 μm), cylindrical to oblong-ellipsoid basidiospores (5.8–9.1 × 2.7–5 μm), and growth on Eucalyptus. Fomitopsis ginkgonis sp. nov. was found from China. It is characterized by its pileate, imbricate, hard corky basidiomata, pinkish buff to cinnamon-buff pore surface, cylindrical basidiospores (7.2–9 × 2.2–3 μm), and growth on living Ginkgo biloba.

Sieverdingia gen. nov., S. tortuosa comb. nov., and Diversispora peloponnesiaca sp. nov. in the Diversisporaceae (Glomeromycota)

Abstract

Phylogenetic analyses of 18S–ITS–28S nuc rDNA sequences indicated that the arbuscular mycorrhizal fungus originally described as Glomus tortuosum and later transferred to the genus Corymbiglomus represents a separate, previously unrecognized clade at the rank of genus in the family Diversisporaceae (order Diversisporales, phylum Glomeromycota). The analyses located the clade between clades representing the genera Desertispora and Redeckera. Consequently, a new genus, Sieverdingia, was erected, with S. tortuosa comb. nov. The unique morphological feature of S. tortuosa is the formation of glomoid-like spores with a single-layered spore wall covered with a hyphal mantle. Importantly, the erection of Sieverdingia clarified the definition of Corymbiglomus, which currently consists of three species producing glomoid-like spores with one, three- to four-layered spore wall. The features of the innermost layer, which is hyaline, laminate, flexible to semi-flexible, indicate that it is a synapomorphy of Corymbiglomus. The definitions of Corymbiglomus and its species were emended. Moreover, the distribution of S. tortuosa and the three species of Corymbiglomus was discussed based on own studies, literature data, and molecular sequences deposited in public databases. We concluded that the distribution of S. tortuosa and C. globiferum known in environmental studies based on their partial 28S nuc rDNA sequences only may be understated because the main molecular characteristics distinguishing these species reside outside the 28S region. Finally, we described a new species in the genus Diversispora originating from Mediterranean dunes of the Peloponnese peninsula, Greece. The same phylogenetic analyses mentioned above indicated that the closest relative of the new species, producing dark-coloured spores, is D. clara, whose spores are creamy white at most.

Debunking Acroconidiella

Abstract

Acroconidiella was proposed to accommodate Acroconidiella tropaeoli, a fungal species causing leaf spots on Tropaeolum majus. At the time, it was recognized as deserving to be treated as a distinct genus because, although being somewhat similar to Alternaria, it did not present muriform conidia formed in chains. More recent observations of A. tropaeoli in culture forming acropetal conidial chains, and the recognition of several non-dictioconidial species as belonging to Alternaria, prompted a reappraisal of the genus, starting with the re-examination of the type species. Samples of Acroconidiella tropaeoli, and also of Acroconidiella trisepta, were recollected in Brazil, and a study involving an analysis of their morphology, under light microscopy and SEM, and a molecular phylogenenetic analysis was performed. A multi-gene phylogeny, including the large subunit of the nrDNA (nc LSU rDNA), internal transcribed spacer (ITS) region, translation elongation factor 1-α (EF1), and polymerase II second largest subunit (RPB2), placed A. tropaeoli within Alternaria, close to A. sonchi and A. cinerariae. The ITS and nc LSU rDNA phylogenetic study of A. trisepta placed it within Dendryphiella. The new combination Dendryphiella trisepta comb. nov is proposed to accommodate A. trisepta. Nevertheless, the new name Alternaria obtusa is proposed for Acroconidiella tropaeoli since it could not be recombined into Alternaria tropaeoli because this name is already in use for another valid (and distinct) species in this genus described from India. This study showed that Acroconidiella is an artificial genus which is now rejected, since its type species belongs to Alternaria—which has nomenclatural priority over Acroconidiella. Other species placed in Acroconidiella, given below, await reappraisal in order to determine their correct taxonomic affinity.

Botryosphaerialean fungi causing canker and dieback of tree hosts from Mount Yudu in China

Abstract

The order Botryosphaeriales includes many latent fungal pathogens with a wide range of woody hosts. The taxonomy of these pathogens has been difficult due to the use of poorly informing markers in phylogenetic analyses and the lack of good morphological characters. Many genera and families in this order have not yet been systematically studied in different hosts and from different regions. In this study, a total of 29 fungal strains from the Aplosporellaceae and Botryosphaeriaceae were isolated from branches or twigs with symptoms of canker and dieback disease in Mount Yudu of China. Morphology and multigene analyses (ITS, LSU and TEF1-α) indicated five distinct lineages, including Aplosporella javeediiBotryosphaeria dothideaDiplodia quercicola sp. nov., Phaeobotryon aplospora sp. nov. and Phaeobotryon rhois. Diplodia quercicola is characterized by multiloculate conidiomata, producing oblong to cylindrical, thick-walled, hyaline, aseptate conidia. Phaeobotryon aplospora is characterized by pulvinate, multiloculate conidiomata, producing ellipsoid to oblong, brown, aseptate conidia. The new species differ from related species phylogenetically and ecologically and in morphological features.

Correction to: Two new species of Clavulina and the first record of Clavulina reae from temperate Abies religiosa forests in central Mexico
There is an error in the original publication of this paper. Authors first and last names have been interchanged. The correct presentation is given above.

Resolving the phylogenetic position of Caeoma spp. that infect Rhododendron and Chrysomyxa from China

Abstract

Many rust fungi that infect Rhododendron belong to the genus Chrysomyxa or the anamorph genus Caeoma. Their morphological resemblance suggests a close taxonomical relationship, however, their phylogenetic relatedness remains unknown. To reveal the phylogenetic affinity and clarify informative morphological characters, we analyzed the sequences of the internal transcribed spacer region of the nuclear ribosomal DNA of 56 isolates representing four species of Caeoma and their allied genus Chrysomyxa, which infect Rhododendron from China. The analysis revealed that Caeoma and Chrysomyxa cluster in the same clade and intermix, thus new combinations in Chrysomyxa have been provided for Caeoma that infect Rhododendron. We also provide expanded descriptions and illustrations of the aecia of Chrysomyxa yunnanensis and the uredinia of Chrysomyxa zhuoniensis for the first time. This study advances our understanding of evaluating some asexually typified generic names of rust fungi using molecular data to determine their correct placement.

Distribution and genetic diversity of Beauveria species at different soil depths in natural and agricultural ecosystems

Abstract

This study aimed to analyze vertical distribution and diversity of Beauveria species throughout the soil profile within farmland and forest habitats to obtain an accurate view of Beauveria density and diversity associated with a particular soil layer. The analysis included a total of 72 soil samples collected at four depths: 0–5, 5–10, 10–15, and 15–20 cm. Of the soil samples, 43 (60%) were positive for Beauveria, producing a total of 641 isolates. Of the positive samples, 28 (65%) were from depths of 0–5 and 5–10 cm while only 15 (35%) from depths of 10–15 and 15–20 cm. Further, for the 29 negative samples, 21 (72%) of them were from depths of 10–15 and 15–20 cm. Higher fungal frequency was found in forest habitat, 462 isolates in 21 positive samples (72%), than from farmland, 179 isolates in 22 positive samples (28%). The highest fungal density (577 isolates, 90%) was recorded in the two top layers (0–5 and 5–10 cm) and decreased significantly as the soil depth increased. Only two species B. bassiana and B. pseudobassiana were identified and co-habited along the whole soil profile. Beauveria pseudobassiana was more strongly affiliated with forest (79%) than farmland (27%) and vice-versa for B. bassiana (21% and 73%, respectively). For both species, the haplotypic diversity varied throughout the soil profile and the highest diversity values were recorded within the soil depths 0–5 and 5–10 cm. This study suggested that the soil band 0–10 cm could be adopted as the standardized depth for soil sampling for ecological studies of Beauveria. It will be important to perform exhaustive soil sampling in different seasons and at different soil depths to validate this hypothesis.

A new and unusual species of Hericium (Basidiomycota: Russulales, Hericiaceae) from the Dja Biosphere Reserve, Cameroon

Abstract

Tropical rainforests form the most species-rich biome on the earth. The Dja Biosphere Reserve (DBR) in Cameroon is a biodiverse tropical forest characterized in part by upland monodominant stands of the ectomycorrhizal (ECM) Gilbertiodendron dewevrei and ECM Uapaca spp. scattered along river banks. This mostly primary Guineo-Congolian evergreen forest harbors natural populations of large megafauna and numerous plant and fungal species. Studies have indicated that some ECM fungal groups of the large order Russulales are abundant in certain localities in the tropics, including the DBR. However, currently, other predominantly wood-decaying families of Russulales are poorly represented in Africa. For example, only three records of the saprotrophic genus Hericium (Russulales, Hericiaceae) are known from the African continent. Here, we describe a new species of Hericium recently collected from the DBR. Morphological characteristics and molecular phylogenetic analyses support placement of the Cameroonian collection in Hericium and its recognition as a new species within a larger H. coralloides species complex. The new species, H. bembedjaense, differs from H. coralloides in its smaller basidiospores (2.6–3.0 × 1.7–2.2 μm compared to 3.5–5.0 × 2.8–4.2 μm) and longer basidia (up to 27.0 μm compared to 15.0 μm). It differs from all other described Hericium species in the production of pleurocystidia. This is the first species of Hericiaceae known from sub-Saharan lowland tropical evergreen forests. This study highlights the need to increase fungal sampling in species-rich tropical forests such as those of the Congo Basin.

Three new Coccomyces species from Shennongjia National Nature Reserve in China

Abstract

Shennongjia National Nature Reserve is an old-growth forest in China with high biodiversity. But only three species in Rhytismataceae had been reported here. Based on morphological and molecular evidence, specimens of Coccomyces collected in Hubei were proposed here as three new species, named Coccomyces fagicolaC. quercicola, and C. shennongjiaensis. Phylogenetic analyses were inferred based on combined nuclear large subunit ribosomal DNA (nrLSU) and mitochondrial small subunit ribosomal DNA (mtSSU) as well as internal transcribed spacer (ITS).

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