Species diversity, molecular phylogeny and ecological habits of Cyanosporus (Polyporales, Basidiomycota) with an emphasis on Chinese collections

Cyanosporus is a genus widely distributed in Asia, Europe, North America, South America and Oceania. It grows on different angiosperm and gymnosperm trees and can cause brown rot of wood. Blue-tinted basidiomata of Cyanosporus makes it easy to distinguish from other genera, but the similar morphological characters make it difficult to identify species within the genus. Phylogeny and taxonomy of Cyanosporus were carried out based on worldwide samples with an emphasis on Chinese collections, and the species diversity of the genus is updated. Four new species, C. flavus, C. rigidus, C. subungulatus and C. tenuicontextus, are described based on the evidence of morphological characters, distribution areas, host trees and molecular phylogenetic analyses inferred 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 largest subunit of RNA polymerase II (RPB1), the second largest subunit of RNA polymerase II (RPB2), and the translation elongation factor 1-α gene (TEF). Our study expanded the number of Cyanosporus species to 35 around the world including 23 species from China. Detailed descriptions of the four new species and the geographical locations of the Cyanosporus species in China are provided.

First Report of Puccinia thaliae Causing leaf rust on Canna indica in Malaysia

Canna indica L. (family Cannaceae), locally known as Bunga Kana, is a perennial plant grown as a source of starch and for ornamental purposes in Malaysia. During June 2021, Bunga Kana with rust symptoms and signs were collected from the Universiti Malaysia Sabah in the province of Sabah. The severity was 95%, and the incidence was 90%. Yellow uredinia were observed primarily on the abaxial surface of the leaves. As the disease progressed, leaves were covered with coalescing pustules, and chlorosis and brown necrosis developed. Microscopic examination of pustules revealed the presence of urediniospores and teliospores. Urediniospores were round to ovoid in shape, yellow, and echinulate, 17.7 to 24.6 x 26.8 to 45.2 μm, with two equatorial pores. Teliospores were elongate-clavate, with rounded apex, yellow contents, 18.3 x 20.2 to 45.8 x 53.9 μm, with a short pedicel. Yellow urediniospores were collected using a fine brush, and genomic DNA was extracted using lysis buffer [Tris-HCl (0.1M, pH 9.5), NaCl (1M), EDTA (0.5M, pH 8)] prior to heating at 95°C for 10 min. KOD One PCR master mix containing hot-start modified KOD DNA polymerase was used for PCR amplification. The 28S ribosomal RNA gene was amplified using primers Rust28SF (Aime et al. 2018) and LR5 (Vilgalys and Hester 1990). BLASTn analysis of the newly generated 28S ribosomal RNA gene (OK462969) in GenBank revealed a 99% sequence identity to Puccinia thaliae Dietel (JX206994 of 28S ribosomal RNA gene). The morphological and molecular characterization of the rust fungus matched P. thaliae described by Padamsee and McKenzie (2012). Koch's postulates were performed with spray inoculations of urediniospores suspended in water (106 spores/ml) on leaves of three healthy Bunga Kana plants, while water was sprayed on three additional Bunga Kana plants which served as control. The inoculated Bunga Kana plants were covered with plastics for 48 h at 25°C in the dark, and then placed in the greenhouse. Symptoms and signs similar to those of the field collection occurred after 13 days post inoculation. No symptoms occurred on controls. Leaf rust on Bunga Kana plants caused by P. thaliae has been reported in Europe (Talhinhas et al. 2016), Hawaii (Nelson 2013), India (Gopi et al. 2014), Mexico (Cedas de Jesús et al. 2018), Nepal (Adhikari and Durrieu 2016), New Zealand (Padamsee and McKenzie 2012), Singapore (Neo and Tham 2010) and South Africa (van Jaarsveld et al. 2006) over the past fifteen years. To our knowledge, this is the first report of P. thaliae causing leaf rust on C. indica in Malaysia. Our findings expand the geographic range of P. thaliae and indicate it could be a potential threat limiting the starch production of C. indica in Malaysia.

Taxonomy and Phylogeny of the Favolaschia calocera Complex (Mycenaceae) with Descriptions of Four New Species

Favolaschia calocera was originally described from Madagascar, and reported to have a worldwide distribution. In the current study, samples of the Favolaschia calocera from Central America, Australia, China, Kenya, Italy, New Zealand, and Thailand were analyzed by using both morphological and molecular methods. Phylogenetic analyses were based on the internal transcribed spacer (ITS) dataset, and the combined five-locus dataset of ITS, large subunit nuclear ribosomal RNA gene (nLSU), the small subunit mitochondrial rRNA gene (mt-SSU), the small subunit of nuclear ribosomal RNA gene (nu-SSU), and the translation elongation factor 1α (TEF1). Our study proves that Favolaschia calocera is a species complex, and six species are recognized in the complex including four new species. Three new species F. brevibasidiata, F. brevistipitata, and F. longistipitata from China; and one new species F. minutissima from Asia. In addition, Favolaschia claudopus (Singer) Q.Y. Zhang & C. Dai, earlier treated as a variety of Favolaschia calocera R. Heim, were raised to species rank. Illustrated descriptions of these five new taxa are given. An identification key and a comparison of the characteristics of species in the Favolaschia calocera complex are provided.

Multi-Gene Phylogeny and Taxonomy of Hydnellum (Bankeraceae, Basidiomycota) from China

The genus Hydnellum is an important group of stipitate hydnaceous fungi which can form ectomycorrhiza with many species of woody plants. In recent decades, the frequency and number of basidiocarps observed in China have been declining significantly. So far, however, we know little about the species diversity of Hydnellum in China. In this study, we conducted molecular phylogenetic analyses based on sections of multiple loci, including the large subunit of nuclear ribosomal RNA gene (nLSU), the internal transcribed spacer regions (ITS), the small subunit of nuclear ribosomal RNA gene (SSU) and the second-largest subunit of RNA polymerase II gene (RPB2), as well as morphological studies, of collected samples of Hydnellum from China. We also inferred Maximum Likelihood and Bayesian phylogenies for the order Thelephorales from the dataset of the combined nLSU and ITS. This study has revealed the phylogenetic position of Hydnellum in the order Thelephorales, and phylogenetically confirmed ten major clades in Thelephorales; Twenty-nine taxa are proposed, described or reported, including 10 new subgenera (Hydnellum subgenus Hydnellum, subg. Caesispinosum, subg. Croceum, subg. Inflatum, subg. Rhizomorphum, subg. Scabrosum, subg. Spongiosum, subg. Subindufibulatum, subg. Violaceum and subg. Zonatum), 11 new species (Hydnellum atrorubrum, H. atrospinosum, H. bomiense, H. brunneorubrum, H. fibulatum, H. granulosum, H. inflatum, H. rubidofuscum, H. squamulosum, H. sulcatum and H. yunnanense), 3 newly recorded species (H. caeruleum, H. peckii and H. spongiosipes) and 5 notable specimens (Hydnellum sp 1, H. sp 2, H. sp 3, H. sp 4 and H. sp 5). A classification system based on the morphological characteristics (especially the hyphal structure types) and molecular analyses is proposed to accommodate most species in Hydnellum. The distinguishing characters of the subgenera and the new species with their closely related taxa are discussed. A key to the species of Hydnellum from China is provided.

Case Report: First Report of Disseminated Trachipleistophora hominis Infection in an AIDS Patient from Thailand

Microsporidial myositis caused by Trachipleistophora hominis is a life-threatening and emerging microsporidiosis among immunocompromised hosts. This article reports a case of disseminated microsporidiosis caused by T. hominis in southern Thailand. The patient had HIV and presented at the clinic with incapacitating muscle pain. She was diagnosed with disseminated microsporidiosis. Molecular identification revealed the sequence of 16S ribosomal RNA gene involving sequences sharing 99% nucleotide identity with T. hominis from an Australian patient. To our knowledge, this is the first study to report the detection of T. hominis microsporidia in an HIV patient in Thailand.

Two new brown rot polypores from tropical China

Brown-rot fungi are types of fungi that selectively degrade cellulose and hemicellulose from wood and are perhaps the most important agents involved in the degradation of wood products and dead wood in forest ecosystem. Two new brown-rot species, collected from southern China, are nested within the clades of Fomitopsis sensu stricto and Oligoporus sensu stricto, respectively. Their positions are strongly supported in the Maximum Likelihood phylogenetic tree of the concatenated the internal transcribed spacer (ITS) regions, the large subunit of nuclear ribosomal RNA gene (nLSU), the small subunit of nuclear ribosomal RNA gene (nuSSU), the small subunit of mitochondrial rRNA gene (mtSSU), the largest subunit of RNA polymerase II (RPB1), the second largest subunit of RNA polymerase II (RPB2) and the translation elongation factor 1-α gene (TEF1) sequences. Fomitopsis bambusae, only found on bamboo, is characterised by its resupinate to effused-reflexed or pileate basidiocarps, small pores (6–9 per mm), the absence of cystidia, short cylindrical to oblong-ellipsoid basidiospores measuring 4.2–6.1 × 2–2.3 μm. Oligoporus podocarpi is characterised by white to pale cream pore surface, round or sometimes angular pores (5–6 per mm), broadly ellipsoid to reniform basidiospores measuring 3.8–4.2 × 2–2.3 μm and growing on Podocarpus. Illustrated descriptions of these two novel species, Fomitopsis bambusae and Oligoporus podocarpi, are provided.

Dental biofilm and its ecological interrelationships in ovine periodontitis

Introduction. Periodontitis, one of the most common oral disorders in sheep, is caused by a mixed and opportunistic microbiota that severely affects the health and welfare of animals. However, little is known about the ecological processes involved and the composition of the microbiota associated with the development of the disease. Hypothesis/Gap Statement. Using high-throughput sequencing of the 16S ribosomal RNA gene and network analysis it would be possible to discriminate the microbiomes of clinically healthy sheep and those with periodontitis and possibly identify the key microorganisms associated with the disease. Aim. The present study aimed to characterise the composition of dental microbiomes and bacterial co-occurrence networks in clinically healthy sheep and animals with periodontitis. Methodology. Dental biofilm samples were collected from ten sheep with periodontitis and ten clinically healthy animals. Bacteria were identified using high-throughput sequencing of the 16S ribosomal RNA gene. Results. The most prevalent genera in the dental microbiota of sheep with periodontitis were Petrimonas , Acinetobacter , Porphyromonas and Aerococcus . In clinically healthy animals, the most significant genera were unclassified Pasteurellaceae, Pseudomonas, and Neisseria. Fusobacterium was found at high prevalence in the microbiomes of both groups. The dental microbiota of sheep in the two clinical conditions presented different profiles and the diversity and richness of bacteria was greater in the diseased animals. Network analyses showed the presence of a large number of antagonistic interactions between bacteria in the dental microbiota of animals with periodontitis, indicating the occurrence of a dysbiotic community. Through the interrelationships, members of the Prevotella genus are likely to be key pathogens, both in the dental microbiota of healthy animals and those with periodontitis. Porphyromonas stood out among the top three nodes with more centrality and the largest number of hubs in the networks of animals with periodontitis. Conclusion. The dental biofilm microbiota associated with ovine periodontitis is dysbiotic and with significant antagonistic interactions, which discriminates healthy animals from diseased animals and highlights the importance of key bacteria, such as Petrimonas , Porphyromonas , Prevotella and Fusobacterium species.