A taxonomic revision of the hitherto monotypic genus Blumeria was conducted incorporating multi-gene sequence analyses, host preference data and morphological criteria. The sequenced loci included rDNA ITS, partial chitin synthase gene (CHS1), as well as fragments of two unnamed orthologous genes (Bgt-1929, Bgt-4572). The combined evidence led to a reassessment and a new neotypification of B. graminiss. str. (emend.), and the description of seven additional species, viz. B. americana sp. nov. (mainly on hosts of the Triticeae), B. avenae sp. nov. (on Avena spp.), B. bromi-cathartici sp. nov. (on Bromus catharticus), B. bulbigera comb. nov. (on Bromus spp.), B. dactylidis sp. nov. (on Dactylis glomerata as the main host, but also on various other hosts), B. graminicola sp. nov. (on Poa spp. as principal hosts, but also on various other hosts), and B. hordei sp. nov. (on Hordeum spp.). Synonyms were assessed, some were lectotypified, and questionable names previously associated with powdery mildew on monocots were discussed although their identities remained unresolved. Keys to the described species were developed.
The genus Aciculosporium (Clavicipitaceae, Hypocreales, Ascomycota)was established in 1908 for A. take, which is the causal fungus of witches’ broom of bamboo. Although the original description was valid at that time, a type specimen for A. take has not been designated. To standardize the use of this genus and species name, a neotypification and reference specimen of A. take are proposed. Multilocus phylogenetic analyses based on DNA sequences from 28S rDNA, TEF, Tub2, Mcm7, and RPB2 revealed that A.sasicola is from a different lineage to A. take, and other specimens from wavyleaf basket grass (Oplismenus undulatifolius) represent a distinct species proposed here as Aciculosporium oplismeni sp. nov. Chemical analysis using mass spectrometry and nuclear magnetic resonance spectroscopy showed that A. take produces four proline-containing cyclic dipeptides, which are moieties of ergot alkaloids. However, ergot alkaloids, lolines, peramine, indole-diterpenes, and lolitrem were not detected in the culture solvent. This study offers clarification of the lineage and morphology of this genus.
During surveys conducted on freshwater fungi from Vietnam, a new aquatic anamorphic fungus was isolated from decaying leaves in Vietnam. The fungus produced phialidic, swollen conidiophore and conidiogenous cells with one-celled conidia with four very tiny lobes. Based on its conidial development and other morphological characteristics, we confirmed that this is a novel fungus and described it as P. ambigua sp. nov. Phylogenetic analyses of P. ambigua based on the LSU nrDNA sequences showed that this fungus clusters in a single clade with the two known Polylobatispora spp. with 97% bootstrap value which is sister with Pseudoprobiscisporaceae. The Polylobatispora clade is nested in the Attracrosporales, Sordariomycetes. Furthermore, in this study two known species of Polylobatispora (P. deltoidea and P. quinquecornuta) were also isolated and illustrated.
MicroRNAs are essential regulators of gene expression and have been extensively studied in plants and animals; however, few reports have been published in mushrooms. Po-MilR-1 is a novel microRNA with a length of 22 bp in Pleurotus ostreatus. The secondary structures of five precursors and the target genes of Po-MilR-1 were predicted. Expression profile analysis showed Po-MilR-1 had specific expression in the primordium and fruiting body. To explore its physiological function, Po-MilR-1 was overexpressed in P. ostreatus. The transformants showed slow mycelium growth rate and abnormal pileus with irregular edge, which suggested Po-MilR-1 plays an important role in P. ostreatus development. Additionally, Po-MilR-1 and one of its target hydrophobin genes POH1 had opposite temporal expression profiles in the primordium and fruiting body, which revealed that Po-MilR-1 may perform its physiological function through the negative regulation of POH1. This study explored the development-related function of a mushroom microRNA and will provide a reference for other microRNAs.
Ophiocordyceps xuefengensis is an ethnopharmacological fungus with broad pharmacological properties. Light is a critical environmental factor for the stromata formation and development of many fungi. In this study, photomorphogenesis and blue light receptor genes were studied using a strain of O. xuefengensis. Light represses vegetative growth, but conidia linked to stromata can be observed under both light and dark conditions. Light and dark conditions had little effect on the accumulation of polysaccharides and adenosine. The genes Oxwc-1 and Oxwc-2 encoding photoreceptors of O. xuefengensis were cloned and predicted to possess polypeptides of 937 and 525 amino acids, respectively. A phylogenetic analysis based on fungal WC-1/2 supported OxWC-1 and OxWC-2 were photoreceptor. The expression of both the Oxwc-1 and Oxwc-2 genes reached a maximum after receiving light stimulation for 15 min, which might relate to the inhibition of stromata growth.
Erysiphe actinidiicola on Actinidia polygama is described based on morphological and molecular data. Erysiphe actinidiicola is distinguished from E. actinidiae var. actinidiae by having irregularly to dichotomously branched chasmothecial appendages, larger chasmothecia sizes and numbers of asci per chasmothecium. Molecular analyses indicated that this species forms a clade separated from E. actinidiae var. actinidiae. An epitype is proposed for E. actinidiae var. actinidiae with ex-epitype sequences. A powdery mildew found on Limonium tetragonum is tentatively described as Erysiphe sp. This species is distinguished from E. limonii, a powdery mildew on Limonium spp., based on the DNA sequence differences in the 28S rDNA and internal transcribed spacer region as well as the morphological differences in the length of the conidiophores. This is the first record of powdery mildew on L. tetragonum in the world.
Neoboletus infuscatus (Boletaceae, Boletales) is described as a new species from Yinggeling of Hainan Tropical Rainforest National Park, southern China. It is morphologically characterized by a large basidioma with a nearly glabrous, brownish yellow, yellowish brown to pale brown pileus, pores orangish red when young, yellowish brown to brown when old, context and hymenophore staining blue when injured, a yellow stipe with red punctuations, surfaces of the pileus and the stipe usually covered with a thin layer of white pruina when young. Phylogenetic analyses of DNA sequences from part of the 28S gene, the nuclear rDNA internal transcribed spacer (ITS) region, and part of the translation elongation factor 1-α gene (TEF1) also confirm that N. infuscatus forms an independent lineage within Neoboletus. Detailed morphological description, color photos of fresh basidiomata and line-drawings of microstructures are provided.
A novel, wood-inhabiting jelly fungus from China is described as a new species, Exidia qinghaiensis (Basidiomycota: Auriculariaceae). Phylogenetic analyses were based on sequences of the nuclear ribosomal DNA internal transcribed spacer (nrITS) and large subunit (nrLSU), RNA polymerase II second largest subunit (RPB2), and translation elongation factor 1-α (Tef1) regions. Sequences of the new taxon formed a sister group to Exidia thuretiana, a species known from Europe and Asia, and distant to sequences of Exidia repanda from Europe. Fruiting bodies are cushion-shaped to irregularly lobed and yellowish brown, basidiospores are hyaline, allantoid (averaging 12.7 × 3.4 μm; average length/width is 3.7), and the host is Betula. The new species also can be distinguished by nrITS, nrLSU, RPB2, and Tef1 sequences. Our multigene phylogeny supports an Exidia including Exidia japonica, type species of Tremellochaete, but defining generic limits in Auriculariaceae will require more extensive taxon sampling.