Mycoscience最新文献

In the search for new strains of edible mushrooms in the Brazilian Amazon Forest, we found Lentinula specimens different from Lentinula raphanica. These were described morphologically and evaluated phylogenetically within the Lentinula clade. The mating system was determined, and interbreeding compatibility with L. raphanica was verified. The basidiomata have a cinnamon or deep orange to fulvous brown, moist to dry pileus, occasionally with whitish scales; crowded whitish cream lamellae; and an eccentric to lateral stipe. The typical, predominant basidiospores are 4.4-7.2 µm in length. Endogenous, elongate (7.8-14 µm) basidiospores were also found in some specimens. The long spores seem rare and occasional, but nonetheless a novelty for the group. Basidia are homogeneous in size, cheilocystidia are pyriform or bulboid, and caulocystidia are long and spheropedunculate. The hyphae of the pileipellis are pigment-encrusted. The characteristics match those of Agaricus ixodes originally described from Guyana, currently a synonym of Lentinula boryana. In the phylogenetic trees, such taxon appears distinct from L. boryana and sister to L. raphanica with strong support. This unique lineage was confirmed to be reproductively isolated from sympatric L. raphanica strains. Lentinula ixodes comb. nov. is the second species of the genus reported in the Amazon Forest.

In this work, we characterize naturally occurring mycorrhizae formed by Amanita viscidolutea on Guapira opposita in the Atlantic Forest in Brazil. We sequenced the rDNA ITS region from the mycorrhizae and basidiomata to identify both symbionts. Amanita viscidolutea mycorrhizae were up to 43 mm long, mostly simple, and unbranched to irregularly pinnate. The fungal mantle surface was velvety to slightly cottony and white to yellowish with silver patches. Hyphal strands were infrequently present. Although the fungal mantle consisted of clampless hyphae, emanating hyphae and hyphal strands had sparsely distributed clamp connections. A unique character of the mycorrhizae was the absence of a Hartig net.

The bark of live trees provides an important microhabitat for corticolous myxomycetes. However, the association between the presence of myxomycetes and health of host trees has not been studied in detail. In this study, we aimed to investigate the relationship between tree vitality and myxomycetes on the bark of Cryptomeria japonica trees in a montane forest in western Japan. The vitality of trees was categorized into four grades based on the visual assessment of tree shape and leaf density in the upper branches. Myxomycetes on the bark surface were examined using the moist chamber culture method. A decline in tree vitality increased bark pH and decreased electrical conductivity of the bark exudates. Seventeen myxomycete species were recorded in 74 C. japonica trees. The structure of myxomycete communities varied between healthy and unhealthy trees, and species diversity increased as the vitality declined. The relative abundance of Cribraria confusa decreased as the vitality declined, while that of Paradiacheopsis solitaria increased. The results showed that acidophilic myxomycetes grew on healthy C. japonica bark, but changes in bark pH associated with vitality decline led to the weakening of acidity and shifted the community structure; thus, corticolous myxomycete diversity was enhanced as tree vitality decline.

Phyllactinia verruculosa is a powdery mildew species (Erysiphaceae, tribe Phyllactinieae) so far only known from its type material collected in China on Indigofera scabrida in 1992, which only comprised the sexual morph. Two asexual morph samples were observed, one was collected on I. tinctoria on the campus of Guizhou University, Guiyang, China, and another one, on I. scabrida, was borrowed from Kunming Institute of Botany, Chinese Academy of Sciences. The anamorphic characters were observed, described and illustrated. The phylogenetic analysis of the combination of internal transcribed spacer regions (ITS) and 28S rDNA sequences showed that Ph. verruculosa is phylogenetically distantly related from other Phyllactinia species. To our knowledge, this is the first record of the asexual morph and first ITS+28S sequences for Ph. verruculosa, and I. tinctoria is a new host record for this species.

Powdery mildew was found on Aristolochia debilis (Aristolochiaceae) in Jiangsu Province and Shandong Province, China. This fungus is characterized by having long conidiophore foot-cells which are straight or curved at the base, and chasmothecia with numerous appendages. Phylogenetic analysis using internal transcribed spacer sequences showed that five sequences on A. debilis determined in this study and two sequences retrieved from Erysiphe sp. on A. debilis formed an independent cluster within the Erysiphe aquilegiae clade with 58% bootstrap support. This powdery mildew differs from allied species of the E. aquilegiae clade in producing longer conidia and conidiophores with longer foot-cells, which are often curved at the base. Morphological observations and molecular phylogenetic analysis revealed a new powdery mildew species, described as Erysiphe ruyongzhengiana.

A previously unknown morel species apparently endemic to Japan is here described. Morchella nipponensis is proposed for this species. This new taxon displays archaic features recalling section Rufobrunnea (pileus lanceolate, few primary alveoli), and a yellow pileus similar to subsection Sceptriformis of section Morchella. The phylogenetic analysis of ITS rDNA, as well as RPB1, RPB2 and TEF1 genes from up to four collections suggests that this morel species represents a basal branch of section Morchella (yellow morels), for which the new subsection Japonicae is proposed.

Fungi in the genus Termitomyces are external symbionts of fungus-growing termites. The three rhizogenic Termitomyces species T. eurrhizus, T. clypeatus, and T. intermedius, and one species similar to T. microcarpus that lacks pseudorrhiza, have been reported from Ryukyu Archipelago, Japan. In contrast, only two genetic groups (types A and B) of Termitomyces vegetative mycelia have been detected in nests of the fungus-growing termite Odontotermes formosanus. In this study, we investigated the relationships between the mycelial genetic groups and the basidiomata of Termitomyces samples from the Ryukyu Archipelago. We found that all the basidioma specimens and the type B mycelia formed one clade that we identified as T. intermedius. Another clade consisted of the type A mycelia, which showed similarity to T. microcarpus, was identified as T. fragilis. Our results indicate that the Japanese T. eurrhizus and T. clypeatus specimens should re-named as T. intermedius.

The phylogeny and taxonomy of Podosphaera filipendulae (including P. filipendulensis, syn. nov.) have been examined. Asian, European and North American collections were examined and the nucleotides sequences of their partial rDNA region were determined. In particular, the relationship between P. filipendulae and P. spiraeae was analysed. The results confirmed P. filipendulae and P. spiraeae as two separate, morphologically similar species. The phylogenetic analysis revealed a similar phylogeny to that of the host genera. Although ITS sequences retrieved from Asian, European and North American specimens of P. filipendulae on various Filipendula spp. are identical to sequences from P. macularis on hop, there is consistently one base substitution at the 5'-end of 28S rRNA gene between the species. This result provides evidence that the hop powdery mildew and P. filipendulae are biologically and morphologically clearly distinguished, and should be maintained as two separate species.

The genus Fraxinus (Oleaceae), known as ash trees, currently comprises 43 recognized species that are distributed in temperate and subtropical regions of the Northern Hemisphere. Two Phyllactinia species, P. fraxini and P. fraxinicola, have been known on Fraxinus spp. so far. In this study, powdery mildews belonging to Phyllactinia were collected on Fraxinus spp. from different areas of the world to make molecular and morphological analyses. These specimens are divided into four distinct molecular phylogenetic groups, which are distinguishable by their morphology and/or host preference. Two new species, viz. P. japonica occurring on F. sieboldina and F. lanuginosa f. serrata, and P. fraxini-longicuspidis on F. longicuspis, are proposed in this study. An epitype is designated for P. fraxini. This study indicates very high host specificity among the four Phyllactinia species on Fraxinus, suggesting that genetic isolation by host specificity played a more important role than geographic segregation in the speciation events of these Phyllactinia species. Evolutionary timing calculated by molecular clock analysis suggests that these powdery mildews diverged in accordance with host phylogeny after divergence of host plants.

Pure cultures of Tuber were isolated from ectomycorrhizal root tips in Abies sachalinensis plantations in Hokkaido, Japan. Their phylogenetic relationships as well as vegetative hyphal characteristics on culture media were reported. Phylogenetic analysis based on the internal transcribed spacer within ribosomal DNA settled well-supported eight lineages within Puberulum, Latisporum, and Maculatum clades in Tuber. Three and one lineages were grouped with undescribed species of Puberulum clade in Japan and that of the Latisporum group in China, respectively. Two lineages were closely associated to but distinct from an undescribed species of Puberulum clade in Japan. One lineage did not group with any sequences in the International Nucleotide Sequence Database (INSD), proposing a new taxon in the Latisporum group. One lineage was grouped with T. foetidum in Maculatum clade. All strains in each lineage displayed yellowish white, thin, filamentous colonies on Melin-Norkrans agar medium. Various differences in morphological characteristics of hyphae on pure cultures of various strains were noted, but they were frequently uncommon among strains of the same taxa. Isolation from ectomycorrhizal root tips can be among the effective ways to acquire pure cultures of Tuber strains.