Mycoscience最新文献

We describe a new truffle species, Tuber torulosum, based on molecular and morphological analyses. This species forms a single globose ascospore per ascus, pale yellow in color, as do Japanese T. flavidosporum and Chinese T. turmericum and T. xanthomonosporum in the Japonicum clade of the Tuber phylogeny. However, it can be distinguished from them microscopically by its whitish tomentose mycelium that partially covers the ascoma surface and the mesh size of its spore ornamentation. Cystidia are moniliform and yellowish to reddish. Molecular phylogenetic analysis using the internal transcribed spacer and partial large subunit regions of ribosomal DNA also supports T. torulosum as a distinct species. On the basis of our results, we provide a key to species in the Japonicum clade.

Two new wood-inhabiting fungal species, Steccherinum hirsutum and S. yunnanense spp. nov., are proposed based on a combination of morphological features and molecular evidence. Sequences of internal transcribed spacer and large subunit region of nuculear ribosomal RNA gene of the studied samples were generated, and phylogenetic analyses were performed using maximum likelihood, maximum parsimony and bayesian inference methods. Steccherinum hirsutum is characterized by an annual growth habit, stipitate basidiocarps with scarlet to red, odontioid hymenial surface, a dimitic hyphal system with clamped generative hyphae negative in Melzer's reaction, and acyanophilous basidiospores measuring 2.5-3.5 × 1.5-2.5 µm. Steccherinum yunnanense is distinguished by resupinate basidiomata with odontioid hymenial surface, a dimitic hyphal system with clamped generative hyphae, strongly encrusted cystidia and ellipsoid, hyaline, thin-walled, smooth basidiospores (3.5-4.5 × 2-3.5 µm). The phylogenetic analyses comfirmed that two new species nest in Steccherinum, in the residual polyporoid clade.

A new species of Lamproderma (Myxomycetes), described herein as L. vietnamense, was recovered in the field on ground litter from mountain subtropical forests (Phia Oắc - Phia Đén National Park) of northern Vietnam. Morphological details were examined by light and scanning electron microscopy. The species is characterized by a distinct and unique combination of morphological features, including a bright blue, shiny and very thin membranous peridium, a small dome-shaped columella, rigid, straight, branched, brown capillitial threads which gradually become pale at the periphery and finally colorless at the tips and small-meshed, banded-reticulate spores with 9-12 meshes across the spore diameter and solid walls without perforations 0.3-0.5 µm high. The stability of the taxonomic characters of L. vietnamense is supported by two well-developed collections found in 2018 and 2019. Partial sequences of three molecular markers (SSU, EF1α, COI) for both collections are identical. A two-gene phylogeny of the first two markers displays the two known accessions as a well-separated entity and indicates affinity of the new species with L. columbinum (the type taxon of the genus), L. violaceum, and several nivicolous Lamproderma species.

The frequent occurrence of mushroom poisoning cases in the wet season in Thailand has long been recognized but has never been quantitatively analyzed. This study aims to analyze mushroom poisoning cases in Thailand between 2003 and 2017 and focused on their association with the rainfall. The results revealed 22,571 cases and 106 deaths in this period. Cases were higher for females than males, adults than children, and agriculturists than people in other occupations. Cases were higher in the northeastern and northern regions than in the central, south, and east regions. There are strong effects of seasonality on mushroom poisoning cases. Over the 15-y period, 17,337 cases occurred in the wet season (May-Sep) compared with 5,234 cases in the dry season (Oct-Apr). The number of monthly poisoning cases were high in men, mature adults, agriculturists, people living in the rural areas and people living in the Northeastern and Northern provinces. Moreover, a strong positive correlation was shown between the number of monthly poisoning cases and the amount of monthly rainfall.

The N-terminal amino acid sequence of the Pleurotus sp. 90 kDa protein was in good agreement with the corresponding sequence of the glycoside hydrolase (GH) family 37 protein (trehalase) from P. ostreatus PC 15 v2.0. The length of the Pleurotus sp. trehalase gene was 2247 bp, encoding a protein of 749 amino acids with a predicted molecular mass of 81.2 kDa. The molecular mass of the recombinant enzyme was estimated to be about 117 kDa by SDS-PAGE. We found that the recombinant enzyme comprised an N-glycosylated sugar chain and that its optimum pH and temperature were 4.5 and 40 ºC, respectively. Moreover, this enzyme exhibited high activity against trehalose exclusively. We found that the enzyme is novel acid trehalase belonging to GH family 37.

Seedlings of Pinus densiflora and Abies sachalinensis were inoculated with Tuber mycelial strains of the Puberulum clade in vitro to examine the morphological characteristics of their ectomycorrhizas. Axenically germinated seedlings were inoculated with the mycelia of five taxa from the Puberulum clade and grown in glass jars for 4 mo in an illuminated incubator. The seedlings were successfully colonized by the inoculated Tuber strains, as confirmed by the nuclear ribosomal internal transcribed spacer barcoding of the synthesized ectomycorrhizas. The ectomycorrhizas were characterized by a pale yellow to brown color, short needle-shaped cystidia, and net-like hyphal arrangement, and epidermoid cells on the mantle surface; notably, these features are similar to the ectomycorrhizas of various Puberulum clade members. As the ectomycorrhizas of different Tuber species are indistinguishable by morphological characters, molecular techniques are necessary to identify ectomycorrhizas formed by Tuber species within the Puberulum clade.

We performed in-vitro germination tests on seeds from five Gastrodia orchids (G. confusa, G. elata var. elata, G. elata var. pallens, G. nipponica, and G. pubilabiata) using one Marasmiaceae and two Mycena isolates. Mycena sp. 1 promoted germination of all five Gastrodia orchids, with root and/or tuber formation observed in G. confusa, G. nipponica, and G. pubilabiata. No additional growth was observed in the other two orchids. Mycena sp. 2 induced G. confusa, G. elata var. elata, and G. nipponica germination, whereas Marasmiaceae sp. 1 induced G. nipponica and G. pubilabiata germination. Phylogenetic analyses indicated that the two Mycena isolates represent distinct lineages within the Mycenaceae. Mycena sp. 1 and Marasmiaceae sp. 1 are closely related to Mycena abramsii and Marasmiellus rhizomorphogenus, respectively. Our results imply that Mycena and marasmioid fungi play important roles in early development in Gastrodia species, and that Mycena fungi in particular may be common mycobionts of Gastrodia species. Root and/or tuber development was observed with four plant-fungus combinations, implying that these associations persist throughout the life cycle, whereas G. elata var. elata may require different associates over time. Our findings will contribute to elucidating the mycorrhizal associations of mycoheterotrophic orchids throughout their life cycle.

Crossbreeding is the most commonly used method in breeding of Lentinula edodes, however low fruiting rate of the hybrids has always caused troubles and barriers for breeders. An early screening method of the fruiting ability could make the breeding work more efficient. In this paper, a rapid and high-throughput laccase activity detection method based on agar diffusion principle was developed. In this way, we investigated the constitutive and inducible extracellular laccase activity of 36 strains in a breeding population of L. edodes on different media and performed a correlation analysis with fruiting ability of these strains. The results showed the laccase activity of mycelium cultured in non-induced medium for 8 d could be used as an early screening index to judge whether it had fruiting ability at the later stage. Early rapid and simple screening method for hybrid populations was established based on laccase activity characteristics of mycelia. 127 strains from another 5 different hybrid populations were used to verify the early screening method. From the validation results, the early screening method was effective, but the appropriate screening threshold was needed to select according to the cross population, which would greatly to improve the breeding efficiency of L. edodes.

Pholiota microspora ("nameko" in Japanese) is one of the most common edible mushrooms, especially in Japan, where sawdust-based cultivation is the most dominant method accounting for 99% of the production. The current strains for sawdust cultivation in Japan are considered to have been derived from a single wild strain collected from Fukushima, Japan, implying that commercial nameko mushrooms are derived from a severe genetic bottleneck. We tested this single founder hypothesis by developing 14 microsatellite markers for P. microspora to evaluate the genetic diversity of 50 cultivars and 73 wild strains isolated from across Japan. Microsatellite analysis demonstrated that sawdust-cultivated strains from Japan were significantly less genetically diverse than the wild strains, and the former displayed a significant bottleneck signature. Analyzing the genetic relationships among all genotypes also revealed that the sawdust-cultivated samples clustered into one monophyletic subgroup. Moreover, the sawdust-cultivated samples in Japan were more closely related than full-sibs. These results were consistent with the single founder hypothesis that suggests that all commercial nameko mushrooms produced in Japan are descendants of a single ancestor. Therefore, we conclude that cultivated P. microspora originated from a single domestication event that substantially reduced the diversity of commercial nameko mushrooms in Japan.

Gomphus matijun, a new edible species, is described from southwestern China based on phylogenetic and morphological evidence. Phylogenetic analyses of the nrLSU and ITS datasets indicated that G. matijun is related to G. crassipes and G. ludovicianus with weak statistical support in maximum likelihood but strong statistical support in Bayesian analyses. Gomphus matijun is characterized by its gray-blue to blue or blue-purple pileus with a round or irregular outline, relatively smaller basidiospores [9-11(-13) × 6-7(-8) μm], mostly 2-spored basidia, and occurs in subtropical fagaceous forests. A key to the known species of Gomphus is provided.