The ascomycete order Diaporthales is reviewed based on recent phylogenetic data that outline the families and integrate related asexual fungi. The order now consists of nine families, one of which is newly recognized as Schizoparmeaceae fam. nov., and two families are recircumscribed. Schizoparmeaceae fam. nov., based on the genus Schizoparme with its anamorphic state Pilidella and including the related Coniella, is distinguished by the threelayered ascomatal wall and the basal pad from which the conidiogenous cells originate. Pseudovalsaceae is recognized in a restricted sense, and Sydowiellaceae is circumscribed more broadly than originally conceived. Many species in the Diaporthales are saprobes, although some are pathogenic on woody plants such as Cryphonectria parasitica, the cause of chestnut blight, and agricultural crops such as canker diseases of soybean and sunflower caused by species of Diaporthe-Phomopsis in both temperate and tropical regions. Members of the Diaporthales such as Apiognomonia-Discula and Diaporthe-Phomopsis are commonly encountered as endophytes of woody plants.

Topographical sensing (thigmotropism) is an essential component of efficient fungal growth. It is an important element in the complex pathway of sensory and mechanical elements that drive and control the growing hyphal tip, a fuller understanding of which will bring the mycological community a step closer to complete comprehension of the hyphal growth mode. Previous work has led us to hypothesize that the stress induced by nutrient deficiency causes structural changes in the hyphal tip that induces a thigmotropic response in Aspergillus niger, a soil fungus that does not display thigmotropism under normal conditions. In this study, we have sought to identify some of the factors that influence this induction of thigmotropism using a novel combination of microengineered substrates and imaging and analysis techniques to quantify thigmotropic behavior in complex hyphal systems. We have shown that the sensitivity of fungal contour sensing appears to be directly linked to nutrient availability and hypothesize that this may be caused by a stress-induced fiattening of the tip and increased immaturity of the hyphal apex.

The phylogenetic relationships of Lactarius volemus and its relatives were investigated using the nucleotide sequences of the nuclear-encoded large subunit ribosomal DNA (LSU rDNA). Thirty-six sequences from L. volemus, L. corrugis, and L. hygrophoroides, including three sequences obtained from the GenBank database, were used in this study. Samples studied were divided into four major subclades (A–D) in both neighbor-joining (NJ) and maximum-parsimony (MP) trees. Lactarius volemus and L. corrugis formed one large clade in both NJ and MP trees (bootstrap value, 100%), which was divided into three subclades (A–C). Subclade A included three clusters of L. volemus strains, i.e., velvet, red, and Chinese types. Subclade B included the common and red types of L. corrugis. Subclade C included the common and yellow types of L. volemus. Subclade D included only one type of L. hygrophoroides. An analysis of the fatty acid composition supported the divisions found in the molecular analysis. Analyses of nucleotide sequence, fatty acid composition, morphological characteristics, and the taste of the fruiting bodies all led us to conclude that the common, velvet, red, and Chinese types of L. volemus, and the common and red types of L. corrugis, may each belong to different species, subspecies, or varieties. Further studies with more material from a wide range of regions are required to conduct taxonomic revision of these types. The LSU rDNA region may be a useful tool to investigate phylogenetic relationships within the section Dulces of the genus Lactarius.

To better understand soil carbon cycling in forest ecosystems, we studied the proportion of fungal sheath area (FSA) in the cross-sectional ectomycorrhizal area in 13 tree species. Ectomycorrhizal samples were collected from subalpine and temperate forests in Japan. The FSA values were in the range of 12% to 56% across all tree species, tree ages, and fungal species. In Abies firma and Quercus serrata, the FSA values were larger in mature trees than in seedlings, whereas no such differences were found in Pinus densiflora and Fagus crenata. In broad-leaved trees, because the plant tissue radii lay within a narrow range, the FSA was affected mainly by the fungal sheath thickness. In conifers, however, the plant tissue radii varied widely among genera, so the FSA was affected by both the plant tissue radius and the fungal sheath thickness. Our findings suggest that the fungal content of ectomycorrhizal tips differs among tree species and fungal species, so that both parameters must be considered in studies of forest carbon cycling. The estimates revealed that data gathering in each type of forest leads to more accurate estimates of the biomass of fungi in ectomycorrhizal tips.

Phylogenetic relationships of seven Haptoglossa isolates were analyzed by using mitochondrial COII amino acid sequences with a data set of 34 peronosporomycetes. Haptoglossa isolates formed a single clade and appeared to be basal to the clade consisting of all other peronosporomycetes. The Haptoglossa clade was divided into two subclades: one clade consisted of five aplanosporic isolates and the other included one aplanosporic and one zoosporic isolate. These results indicate that the genus Haptoglossa is monophyletic, and patterns of infection cell formation reflect more the phylogenetic relationship between the species than patterns of sporogenesis.

We isolated and characterized the class IV chitin synthase gene (Pochs1) from the edible basidiomycetous mushroom, Pleurotus ostreatus. Real-time quantitative RT-PCR analysis of the transcriptional expression pattern of Pochs1 in the course of fruit-body formation of P. ostreatus revealed that the transcriptional level of Pochs1 is higher in the stage of immature fruit body than in the stages of mycelia and mature fruit body. Furthermore, the transcriptional level of Pochs1 in mycelia was shown to have increased significantly by the temperature-downshift treatment, which is one of the important factors for inducing the onset of fruit-body formation of P. ostreatus.

Two fungi collected from submerged woody debris were found to represent hitherto undescribed species of the ascomycete genera Clohiesia and Paraniesslia. They are described as Clohiesia curvispora sp. nov. and Paraniesslia aquatica sp. nov. based on morphological characters. Clohiesia curvispora is characterized by immersed ascomata under a clypeus, and unitunicate, cylindrical asci containing one-celled, curved, elongate-fusiform ascospores. Paraniesslia aquatica is characterized by small, superficial, setose ascomata, and unitunicate, clavate asci containing verrucose, brown ascospores. Each species is illustrated with light micrographs and compared with similar taxa in this article.

The growth pattern of Mucor globosus cultured on a medium with or without cyclic adenosine monophosphate (cAMP) was examined. Branching remarkably increased in a mycelium grown on an agar medium containing cAMP. In submerged culture containing cAMP, some sporangiospores grew spherically and formed yeast-like cells, and others showed hyphal growth. These hyphae showed septation and swelling and formed spore-like structures. When these hyphae were transferred to cAMP-free medium, a germ tube emerged from each compartment. These results show that cAMP has two different effects on the development of hyphae: one is the promotion of branching, and the other is the suppression of polarized growth.

MeOH and water extracts were obtained from 16 species of infected leaves with rust fungi belonging to 18 species in 6 families: Pucciniaceae, Melampsoraceae, Coleosporiaceae, Pileolariaceae, Phragmidiaceae, and Phakopsoraceae. All the extracts of rust-infected plants with telia showed the teliospore-inducing activity for wheat leaf rust (Puccinia recondita f. sp. tritici).

The basidiomycete Lyophyllum decastes was transformed by means of particle bombardment. We isolated five transformants under twelve conditions differing in the two parameters of target distance and helium pressure. The transformation frequency was one transformant/ μg DNA. In the transformants, plasmid DNAs were integrated into the genomic DNA and stably maintained. This is the first report on transformation of L. decastes by particle bombardment.