Seiji Tokumasu

Fungal successions on pine needles fallen at different seasons: the succession of surface colonizers*

Field experiments were carried out to investigate influences of seasonal change on the fungal succession occurring on the surface of decaying pine needles at a moder site in Japan. At different seasons, the needles fallen for a short period were collected and marked, then placed on the surface of the O horizon. The needles were removed at intervals and their fungal communities were examined by using a washing technique. Unlike the successions of interior colonizers studied at the same time, those of surface colonizers observed on the fallen needles at four different times are roughly similar to each other.Thysanophora penicillioides was the major first colonizer on the sample needles from the O horizon, andTrichoderma species followed it. In an experiment started in late autumn, three dematiaceous fungi,Chloridium viride var.chlamydosporis, Sporidesmium omahutaense, andChalara sp., commonly occurred and contributed to the darkening of colonized needles. Seasonal variation in climate may have a stronger effect on internal colonizers than external colonizers of needles.

Fungal succession on pine needles in Germany

The mycofloral succession on the needles ofPinus sylvestris was investigated in Tübingen, southwest Germany. Dead needles attached to the branches (D-type), those caught on branches (C-type) and three types of fallen needles, i.e., freshly fallen (L-type), slightly discolored (OL-type) and almost black needles (F-type) were examined for their fungal flora. Common primary saprophytes were rich on the dead needles on the tree, and on the L-type needles. They were replaced by successive species that contained the well-known species preferring pine needles as their substratum, such asVerticicladium trifidum orSympodiella acicola. Their ecological niches in pine leaf litter and their distribution patterns from a biogeographical viewpoint were discussed.

Mycofloral succession on Pinus densiflora needles on a moder site

Mycofloral succession on decaying pine needles in aPinus densiflora forest on a moder site was investigated in Sugadaira, Nagano Pref., central Japan. Dead needles on the tree, fallen needles obtained from two recognizable sublayers of the L layer and the upper sub-layer of the F1 layer in the organic horizon were examined for their fungal flora using both washing and surface sterilization techniques. The major interior colonizer in freshly fallen needles varied with the season:Chaetopsina fulva in summer andSelenosporella curvispora in the other seasons.Thysanophora penicillioides was a remarkable external colonizer of freshly fallen needles in summer, while soil fungi were external colonizers of such needles in the other seasons. A possible successional change of major fungi with the needle decay was suggested. The observed seasonal alternation of the species colonizing freshly fallen needles was discussed in relation to climatic conditions.

Molecular phylogeny of four selected species of the strictly anamorphic genus Thysanophora using nuclear ribosomal DNA sequences

Abstract To estimate the phylogenetic position of the strictly anamorphic genus Thysanophora among the class Ascomycetes sensu Kirk et al. and to examine the phylogenetic relationships among T. penicillioides and other Thysanophora species, 18S and 28S rDNA (D1 and D2 regions) sequences of 22 strains of four known and two unidentified Thysanophora species were determined and phylogenetically analyzed. The 18S rDNA analysis suggested that all Thysanophora species examined were members of Eurotiomycetidae, Eurotiales, Trichocomaceae. The 28S rDNA analysis indicated that these species were clustered together with Chromocleista, Eupenicillium, Geosmithia, and Penicillium assignable to three subgenera – Aspergilloides, Furcatum, and Penicillium. In the Eupenicillium lineage, a monophyly of T. penicillioides, T. longispora, T. taxi, T. canadensis, and T. cf. canadensis was supported by comparatively high bootstrap values. However, the ex-type strain and two strains of T. longispora isolated in Japan were of different phylogenetic positions. Thysanophora sp. was positioned at the base of the Thysanophora clade, although it was not supported by significant bootstrap values. From the results of this study, we consider that two anamorphic genera, Penicillium and Thysanophora, are clearly distinct in morphology but that they are not phylogenetically separable.

Taxonomic study of the Japanese Dacrymycetes

The class Dacrymycetes is a rather small group of brown-rot wood-decaying jelly fungi characterised by forked basidia and an orange to yellow gelatinous to cartilaginous fruit body. In Japan, dacrymycetous fungi had not been investigated for a long time, justifying a taxonomic re-examination. In the present study we attempted an investigation of the dacrymycetous fungal flora of Japan, and recognised 28 taxonomic entities, including five new taxa, i.e. Dacrymyces ancyleus, D. aureosporus, D. pinacearum, D. subarcticus and Dacryopinax sphenocarpa, and nine new records. Due to the present survey, the total number of dacrymycetous species recorded from Japan increased from 28 to 42. Of the newly described species, Dacrymyces ancyleus is characterised by recurved, cylindrical basidiocarps and hyphae with clamp connections. Dacrymyces aureosporus resembles D. chrysospermus, but differs in wall thickness of its marginal hyphae. Dacrymyces pinacearum and D. subarcticus represent new coelomycetous anamorphic species. Dacryopinax sphenocarpa has sharp, spathulate basidiocarps, and hyphae with clamp connections. Descriptions, illustrations and photographs of fruit bodies are presented with some taxonomic notes. Molecular phylogenetic analyses were conducted to verify the species identification, and the remaining problems in Dacrymycetes taxonomy are discussed based on these data.

Zygospore formation in Mortierella capitata

A novel type of zygospore formation is described in the heterothallic speciesMortierella capitata, which was repeatedly isolated from soils inhabited by pillbugs (Armadillidium vulgare, Isopoda). Zygospore formation was induced on media containing sterilized arthropods. Anisogamy and colorless zygospore walls are shared with other zygosporic species ofMortierella, but a unique feature ofM. capitata is the production of zygospores on elongated macrosuspensors which are covered by branches of the microsuspensors. This kind of zygosporogenesis is termed “capitata-type” here. The taxonomic position ofM. capitata is discussed based on the zygospore characteristics.

Geographical distribution of Sporidesmium goidanichii in pine forests of Japan

The geographical distribution of a saprotrophic hyphomycete,Sporidesmium goidanichii was studied in pine forests of Japan. Using the data of 282 fungal communitles of pine leaf litter collected over a wide range of climatic conditions, the relationships among two indexes of distribution of the species (constancy and abundance) and three climatic variables were analyzed by the multiple regression analysis. The results demonstrated that the mean annual air temperature and the mean annual range (the difference in monthly mean air temperatures between the coldest and warmest months at the study sites) were necessary variables for the prediction of the values of indexes ofS. goidanichii in pine forests of Japan, while the mean annual precipitation was an unimportant factor. The distribution patterns of the fungus along the gradients of two temperature variables were analyzed graphically. The fungus has an optimal climatic area with high values of indexes where is restricted to the center of the warm temperate regions of the main islands. The relationship between the life strategy of the fungus and its temperature-dependent distribution pattern in Japan was also discussed.

A new genus Myconymphaea ( Kickxellales ) with peculiar septal plugs

Myconymphaea yatsukahoi gen. sp. nov. is described in the Kickxellaceae (Kickxellales, Zygomycetes). The fungus is characterised by unicellular sporocladia formed on apical vesicles of sporangiophores, conspicuously long sporangiospores and peculiar septal plugs with prominent protuberances. In addition, a key to all known genera of the Kickxellales is provided.

Coemansia furcata sp. nov. and its distribution in Japan and Taiwan.

Coemansia furcata, isolated from forest soils of Japan and Taiwan, is described and illustrated. This species is characterised by its sporangiophore branching and relatively large sporocladia. Its distribution in soils of Japan and Taiwan is discussed.

Dematiaceous hyphomycetes inhabiting decaying blackish needles of Abies firma and their distribution in the Kanto district, Japan

Dematiaceous mitosporic fungi darkening decaying fir needles on the ground were studied. Fungal communities on decaying, blackish fir needles were investigated in nine sites of the Kanto district, Japan, using a washing method. A total 108 taxa was recorded from 540 sampled needles. Among abundantly occurring dematiaceous fungi,Anungitea continua, A. uniseptata andEndophragmiella uniseptata were recognized as the major colonizers, forming a hyphal network on the surface of decaying fallen needles and darkening them. The effects of climate on the distributions of seven dematiaceous fungi included the major colonizers were analyzed. The abundance (proportion of needles colonized by a fungal species) ofChaetopsina fulva showed a significantly positive correlation with annual mean air temperature at each sampling site. No other significant correlations between the selected climatic factors and the distributions of dematiaceous fungi were recognized.