The remaining unclarified taxon among the seven known pathotypes of host-selective toxin (HST)-producing Alternaria alternata, namely, the strawberry pathotype (the strawberry black leaf spot pathogen), is taxonomically revised and re-described herein. According to our morphological observations, reference isolates of strawberry and Japanese pear pathotypes, which are toxic to leaves of Japanese pear ‘Nijisseiki’, have conidia that are formed in chains of 3–13, usually without lateral branches, after 7 d incubation on potato-carrot agar. The mean size of the conidia is 27–31 × 11–13 μm. Morphological characteristics of the examined isolates are identical to those of A. gaisen rather than A. alternata. A phylogenetic tree obtained by analysis of a combined dataset of ITS, gapdh, rpb2, tef1, Alt a 1, and endoPG sequences also strongly supports both pathotypes as one species, A. gaisen. We re-describe the fungus as A. gaisen Nagano ex Bokura and propose two formae speciales of the species, A. gaisen f. sp. fragariae producing AF-toxin and f. sp. pyri producing AK-toxin. The epitype specimen and ex-epitype culture of A. gaisen are newly designated.

A small blue stipitate-pileate mushroom with porioid hymenophore was found on dead Calamus sp. (Arecaceae) in Taiwan. Microscopic characteristics indicated a placement within the Mycenaceae. ITS as well as partial LSU ribosomal RNA gene sequences analyses showed a close relationship with Mycena illuminans within the Mycenaceae. A new species with completely blue basidiomata, Mycena indigotica, is proposed based on morphological and molecular evidence.

Pleurotus ostreatus is one of the most widespread and favourably cultivated mushrooms in China. The cultivated strains of this species have been frequently exchanged domestically and internationally, but no detailed breeding history has been documented. The frequent domestic and international exchange of strains combined with a non-detailed historical documentation of breeding might have led to confusion about strain names and genetic background. In this study, 91 strains of P. ostreatus, including 57 cultivated and 34 wild strains, were analysed using 21 simple sequence repeat markers developed from the genomic sequence of “P. cf. floridanus”. Among the cultivated strains, 46 were found to possess different allelic patterns. The remaining 11 strains were clustered into five groups, each with their own private alleles, suggesting that 10.5% (6/57) of the cultivated strains were previously labelled with improper names. Our analyses indicate that wild strains harbored greater genetic diversity than the cultivated strains. With regard to the cultivation history of P. ostreatus, the cultivated strains in China have three sources: direct introduction from Europe, domestication from wild strains from China, or hybridisation of the European and Chinese strains. Furthermore, we propose a core collection of P. ostreatus with 34 strains, including 13 wild and 21 cultivated strains. The allele retention proportion of the core collection for the entire collection was 100%.

A new species in the genus Myriostoma (Geastraceae, Basidiomycota) is described from Australia. Phylogenetic analyses of the internal transcribed spacer (ITS) and large subunit (LSU) of nuclear ribosomal DNA, as well as morphological data are evidence that the new species, Myriostoma australianum, is closely related to M. capillisporum from South Africa. Additional collections under M. coliforme from Brazil and USA (New Mexico) were analyzed and confirmed as belonging to M. calongei.

Since 2010, an unknown fungus in the Gnomoniaceae has been found on overwintered leaves and petioles of Styrax obassia (Styracaceae) in Japan. This fungus is characterized by dark brown immersed or partially erumpent ascomata with long necks and fusiform to obovoid asci each with an acute or long tapering stipe. Each ascus bears eight fusiform to filiform ascospores. Our morphological observation and phylogenetic analyses based on the markers LSU, rpb2, and tef-1α indicated that this is a new monotypic genus in the Gnomoniaceae (Diaporthales), and Tenuignomonia styracis gen. et sp. nov. was descried herein. Members of the Gnomoniaceae are commonly isolated as endophytes, saprobes, and plant pathogens from a broad diversity of herbaceous, shade tree, and agriculturally significant plants. We thus carried out a pathogenicity test to determine if T. styracis is the causative agent of leaf blotch on S. obassia. One week after inoculation, this fungus produced small necrotic spots on the leaves and petioles, and all leaves having necrotic spots were abscised in a short time. We thus confirmed that this fungus has weak pathogenicity on S. obassia. This new species may promote early defoliation of S. obassia during the fall.

This study investigated the bacterial communities present on the ectomycorrhizal roots of Laccaria laccata using culture- and cloning-based methods. One soil core was collected from five locations where sporocarps of L. laccata occurred in a chestnut plantation. A total of 10 and 50 ectomycorrhizal root tips of L. laccata were collected from each soil core and subjected to bacterial isolation and cloning. In total, 223 isolates were classified into 35 molecular operational taxonomic units (MOTUs). The majority of MOTUs were infrequent, whereas one MOTU each of Rhizobium and Bradyrhizobium were common across the sampling locations. In the cloning-based method, 77 MOTUs were detected. The majority of these MOTUs were infrequent, whereas one MOTU each of Bradyrhizobium and one taxon of Gammaproteobacteria was common across the sampling locations. These results indicate that Bradyrhizobium is a common member of bacteria present on the ectomycorrhizal roots of L. laccata in the chestnut plantation.

Species of fleshy yellow Cantharellus are known as chanterelles, which are among the most popular wild edible mycorrhizal mushrooms in the world. However, pure culture isolates of Cantharellus are rare. We report an efficient isolation technique of the Japanese golden chanterelle, Cantharellus anzutake, from its ectomycorrhizal root tips. Field-sampled fresh ectomycorrhizal root tips of C. anzutake on various hosts such as pines, spruce, and oaks were vortexed with 0.005% Tween 80 solution, surface sterilized with 1% calcium hypochlorite solution, rinsed with sterilized distilled water, and placed on modified Norkrans’ C (MNC) agar plate medium. Most ectomycorrhizal root tips of C. anzutake produced yellowish mycelial colonies within a few months. In contrast, tissue isolation from basidiomata provided limited cultures of C. anzutake but much contamination of bacteria and molds, even on media that contained antibiotics. The established C. anzutake cultures had clamp connections on the hyphae and contained intracellular oily droplets. These cultured isolates were identified as C. anzutake by sequence analysis of the rRNA internal transcribed spacer (ITS) region and translation elongation factor EF1-alpha (tef-1) genes.

Metabolism of benzoic acids and benzaldehydes are crucial to produce hormones, defense compounds and attractants for pollinators in plants. Tricholoma matsutake contains benzoic acid and benzaldehyde, but their roles have not been fully studied. First we conducted tracer experiments to gain insight into benzoic acid and benzaldehyde biosynthesis in T. matsutake. ¹³C and ²H were incorporated into benzoic acid from uniformly ¹³C- and ²H- labelled _L-phenylalanine and (E)-cinnamate 1 d after supplementation of the precursors without any substitution of ¹³C and ²H. In contrast, no ¹³C and ²H were incorporated into benzaldehyde from these precursors 10 d after the supplementation. The results indicate that T. matsutake has a metabolic pathway to biosynthesize benzoic acid from _L-phenylalanine and (E)-cinnamate in which benzaldehyde is not a metabolic intermediate. However, 30 d after the supplementation of ¹³C- and ²H- labelled _L-phenylalanine, ¹³C and ²H were incorporated into all the carbon and hydrogen atoms of benzaldehyde. In addition, ²H was not incorporated into benzaldehyde from exogenously supplemented ²H-labelled benzoic acid. This result indicates that T. matsutake has a metabolic pathway to biosynthesize benzaldehyde from _L-phenylalanine in which benzoic acid is not an intermediate. Taken together, our results strongly suggest that T. matsutake biosynthesizes benzoic acid and benzaldehyde in separate pathways.

Arbuscular mycorrhizal (AM) fungi form an intimate symbiosis with roots of more than 80% of land plants without eliciting a significant defense response, and how they do so is yet to be determined. Typically, plants mount a defense response upon sensing chitin in fungal walls, and to counteract this response, plant-pathogenic fungi secrete small effector proteins with chitin-binding LysM domains. In the AM fungus, Rhizophagus irregularis, a small, putatively-secreted LysM protein, which we refer to as RiSLM, is among the most highly expressed effector-like proteins during symbiosis. Here, we show that RiSLM expression is reduced during non-functional symbiosis with Medicago mutants, mtpt4-2 and vapyrin. We demonstrate that RiSLM can bind to both chitin and chitosan, and we model the protein-ligand interaction to identify possible binding sites. Finally, we have identified RiSLM homologs in five published R. irregularis isolate genomes and demonstrate that the gene is subject to a high rate of evolution and is experiencing positive selection, while still conserving putative function. Our results present important clues for elucidating a role for a LysM effector, RiSLM, in AM symbiosis.

We isolated Tulasnella spp. from Spiranthes sinensis var. amoena, a Japanese native winter green terrestrial orchid collected in Tsukuba City, Ibaraki Pref., Japan. These isolates were classified into four morphotypes according to morphological characters, i.e., shape of monilioid cells and branch type of monilioid cell chains, while they were separated into five clades by molecular phylogenetic analysis based on the rDNA 5.8S and D1/D2 regions. The four morphotypes and five clades were correlated, and four morpho-phylogenetic groups were identified. Thus, Tulasnella deliquescens including two phylogenetic subgroups and three new species, Tulasnella dendritica sp. nov., Tulasnella ellipsoidea sp. nov., and Tulasnella cumulopuntioides sp. nov., were recognized in this study. In this study, the monilioid cell chain morphology is newly defined, and is suggested as a useful taxonomic characteristic in the asexual stage of Tulasnella spp.