The purpose of application of spontaneous mutation to breeding was to perform the genetic analysis of the pileus-color trait of white mutants (albino) belonging to Pleurotus cornucopiae var. citrinopileatus. Furthermore, an examination of the stipe-apogeotropism loss trait observed during the genetic analysis of the white trait was also added to study its heredity. As a result, it was observed that several recessive genes were responsible for the white trait, whereas only a single recessive gene was responsible for the stipe-apogeotropism loss trait. Linkage analysis revealed that these fruiting-body traits (pileuscolor and stipe-apogeotropism) and their incompatibility factors (A and B) were not linked to each other. In addition, because all the apogeotropism loss mutants were accompanied with a spore deficit mutation, it was assumed that both the mutations were closely related.

Crinipellis dipterocarpi f. cinnamomea, a marasmioid fungus newly recorded from Japan, is reported with a description and illustrations of morphological characters. It was collected from decayed, fallen leaves or branches of Machilus thunbergii and Castanopsis sieboldii in the laurel forest of Chiba Prefecture. By the maximum parsimony analysis of the nuclear rDNA ITS region, C. dipterocarpi f. cinnamomea samples collected from Japan, Thailand, Indonesia and Malaysia were placed within the same well-supported clade. The present analysis supports the idea that the Japanese and Southeast Asian specimens of C. dipterocarpi f. cinnamomea are members of the same taxon.

　 We had already reported that the wood preservative ability of Trichoderma sp. ANCT-05103 immobilized on charcoalparticles was superior for Fomitopsis palustris, Trametes versicolor, and three other wood decaying fungi. In this study, the wood preservative ability of immobilized Trichoderma virens NBRC 31959 on charcoal-particles to wood degradation by the five wood decaying fungi was examined. NBRC 31959 had been selected by antagonistic performance to F. palustris and T. versicolor. The strain immobilized on the particles showed inhibition effects for the degradation by the four strains except by F. palustris. The wood preservative ability of ANCT-05103 immobilized on heat-treated (240-280℃) wood particles instead of the charcoal was poor for F. palustris and T. versicolor. In addition, the charcoal-particles did not have the ability to inhibit wood degradation by the two basidiomycetes. As a result, it was suggested that the combination of the charcoal and ANCT- 05103 produced the superior wood preservative performance.

　 Taxonomy of the genus Fusarium, transition of its species concept, introduction and development of molecular phylogeny and their current conditions have been outlined by reviewing our own studies. Taxonomy of the genus has traditionally been based on the phenotypes represented by the species, mainly their morphological features. Microscopic phenotypes including those in culture are, however, not always stable characters for taxonomy and, therefore, severe arguments on the species definition or their circumscriptions have been conducted among taxonomic workers. Efforts to establish a worldwide reasonable taxonomic system have been facing a lot of difficulties. Molecular-phylogenetic analyses based on DNA sequences of their gene regions, introduced substantially in 1990s, have made a significant influence to the taxonomy of Fusarium. Species concepts of the genus have been converged into those recognizing narrowly splitted species. On the other hand, a lot of cryptic species have been discovered within the previously-known species that were defined briefly. Requirements are to describe and recognize splitted species accurately based on still limited phenotypic features. To obtain constant and stable data for such species delimitation, observation of fungal materials and examination of phenotypic features should become more precise. Consequently, a lot of novel species have been described, in addition to division of well-known species so far. Phenotypically-defined species (i.e., morphological species) are not always equivalent to phylogenetically-recognized species (i.e., molecular-phylogenetic species). To guarantee objectiveness of species definition, novel species are being described based on phenotypic features that are also supported by the phylogenetic analyses. However, limitation of available phenotypic features for the satisfactory definition of these species is becoming serious. A possible new procedure to satisfy requirements of the nomenclatural code is expected for describing taxa based on the direct application of molecular-phylogenetic data for the Fusarium taxonomy.

　Polyporus (Basidiomycota, Polyporales) accommodates morphologically heterogeneous species and is divided into six infrageneric groups based on macromorphological characters. On the other hand, there are allied genera sharing same microscopic characters and the rotting type with Polyporus. Molecular phylogenetic analyses recognizes six major clades containing species of Polyporus and three allied genera. Five of six major clades were characterized by the morphological characters used to define infrageneric groups. It suggests that these morphological characters have phylogenetic significance and reveals the need for a taxonomic revision of Polyporus and its allied genera. A taxonomic study on group Favolus of Polyporus was conducted using phylogenetic and morphological methods. Species of two detected clades are distinguishable by the morphology of the pileus surface. One clade is characterized by species with hyaline to brown cutis, composed of hyaline to brown agglutinated generative hyphae, the other clade accommodates species with radially striate pileus, and lacks any distinct cutis of agglutinated hyphae. The former clade is proposed as Neofavolus gen. nov., typified by N. alveolaris, and the latter clade is segregated as the genus Favolus, typified by F. brasiliensis. Species of Polyporus s. l., Favolus, Neofavolus and Echinochaete in Japan are reviewed and listed in this article.

　Wood-inhabiting fungal communities have an important role in the decomposition of coarse woody debris (CWD) in forest ecosystems. In this review, I summarize the mechanisms of fungal community development in CWD, list the environmental and fungal factors affecting community development, and discuss the effects of interspecific fungal interactions and species richness on CWD decomposition. In wood, the dominant type of interspecific fungal interaction is competition. Hierarchy in competitive abilities among fungal species is believed to be a key determinant of fungal community development and succession in CWD. Environmental factors, such as tree species, temperature, moisture, gaseous regime, and decay stages of CWD, and fungal factors, such as colonization timing and inoculum size, affect the hierarchy of interspecific fungal interactions. Following three mechanisms are proposed for the effects of interspecific fungal interactions on wood decay: (1) the decay ability of the most competitive species; (2) competition as an energy and nutrient cost alters the fungal physiology and influences the wood-decaying abilities of fungi; and (3) resource partitioning and facilitation by primary decomposers stimulates the decay activities of successor fungi. From laboratory incubation and field experiments, positive and negative effects of fungal interactions and species richness on CWD decomposition have been reported.