Ectomycorrhizal fungi play an important role in forest ecosystems. In recent years, forest ecosystems have been subjected to unprecedented pressure due to changes in the natural environment, including climate change, and anthropogenic influences. Forest trees establish symbiotic relationships with a diverse range of ectomycorrhizal fungi possessing various ecological characteristics. Understanding the individual traits of these fungal species is crucial for predicting adaptation to future environmental changes. DNA information has brought many benefits to mycology and has greatly contributed to the ecology of ectomycorrhizal fungi. This review provides an overview of previous research focusing on the genus Rhizopogon and introduces the author's research findings as a case study in alpine ecosystems. Furthermore, this review discussed current challenges and future research directions in the ecological studies of ectomycorrhizal fungi.

This review article reconstructs the presentation at the 67th annual meeting of the Mycological Society of Japan, held in Kumamoto on May 27-28, 2023. The authors discussed the effectiveness of phenotypic analysis and inoculation tests in classifying and redefining plant pathogenic species of the genus Alternaria. In this study, 26 species, including three novel species, were collected and characterized based on their morphology, phylogeny, and pathogenicity. Each examined species exhibited distinct host selectivity, and their experimental host ranges were restricted by plant systematic ranks, including variety, species, genus, tribe, and subfamily. Therefore, it was concluded that integrated species recognition based on morphology, molecular phylogeny, and pathogenicity elucidates the species boundaries of Alternaria.

Four species of Lepiota i.e., L. clypeolaria, L. magnispora, L. ignivolvata and L. clypeolarioides, were collected from Aomori, Yamanashi and Tokyo. The morphological characters of these four species were consistent with their original descriptions. Phylogenetic analysis using nucleotide sequence data of nuc rDNA ITS region supported their identity and independency as four different species. Lepiota ignivolvata (sect. Lepiota) and L. clypeolarioides (sect. Ovisporae) belonged to new Japanese records of these taxa. In the manuscript, the morphological properties and the phylogenetic placement of these specimens are described. Japanese name of L. clypeolaria and L. magnispora were discussed.

The present study reports the identification of two newly recorded species of the genus Rickenella, R. indica and R. mellea, in Japan. Small (1-3 mm wide), parabolic to convex, and never becoming applanate or infundibuliform pileus are characteristic features of R. indica. Rickenella mellea is a subalpine species and it is characterized by its honey-colored, yellowish-beige to reddish yellow-pileus and stipe. Molecular phylogenetic analysis using the ITS region and the LSU of the nuclear rDNA supported their identification based on morphological observations. A key to the known Japanese species of Rickenella and morphologically similar taxa is provided.