Species of Amanita sect. Vaginatae (Fr.) Quél. are challenging to delimitate due to the morphological similarity or morphostasis among different taxa. In this study, a multi-locus (nuc rDNA region encompassing the internal transcribed spacers 1 and 2 with the 5.8S rDNA, the D1–D3 domains of nuc 28S rDNA, partial sequences of translation elongation factor 1-a, and the second largest subunit of RNA polymerase II) phylogeny was employed to investigate the species diversity of the section in eastern China. Sixteen species were recognized, including four new species; namely, A. circulata, A. multicingulata, A. orientalis, and A. sinofulva. They were documented with illustrated descriptions, ecological evidence, and comparisons with similar species. A key to the species of the section from eastern China is provided.

A new species, Leucoagaricus purpurascens, collected from a subtropical region in China, is described based on morphological and molecular data. Leucoagaricus purpurascens is characterized by its small basidiomata with purple discolouration when dried, the pileus with distinct umbo, the amygdaliform, ellipsoidal to oblong basidiospores, and the absence of cheilocystidia. A detailed morphological description, line drawings, colour photographs, and a phylogenetic tree showing the phylogenetic placement of the new species are provided.

In the industrial production of Lentinula edodes and Pleurotus eryngii, slow growth of the mother seed and insufficient hyphal vitality can significantly affect the cultivation process. To shorten the growth period on traditional PDA medium, two strains of L. edodes and P. eryngii were cultured with different proportions of P. tuber-regium and Wolfiporia hoelen sclerotium powders added into the medium to investigate the effect on the mycelial growth. Compared to the PDA, the addition of sclerotia powder significantly enhanced the growth of mycelia, with an optimal addition ratio of 2%. Transcriptome sequencing was performed after culturing L. edodes and P. eryngii on PDA, PDA with 2% P. tuber-regium sclerotium powder, and PDA with 2% W. hoelen sclerotium powder. GO enrichment analysis of the differentially expressed genes (DEGs) of L. edodes and P. eryngii strains cultured in the sclerotia powder media showed significant changes in oxidoreductase and glucosidase activities. Changes were observed in KEGG annotation for carbohydrate metabolism, glycolysis, pyruvate metabolism, and other energy metabolic pathways. Moreover, carbohydrate-active enzyme (CAZyme) family genes were predominantly upregulated. The increase in the activity of CAZyme and oxidoreductases promotes the degradation of nutrients in the sclerotia into small-molecule substances, which explains why the sclerotia powder culture medium promotes mycelial growth.

Hypsizygus marmoreus (Peck) H.E. Bigelow is a commercial edible mushroom includes two primary commercial varieties: brown and white. To reveal the genetic and metabolic differences between these two varieties, genomic and metabolomic comparisons of the white strain F4 and the brown strain B5-15 were performed. The assembled genome sizes were 40,851,948 bp for F4 and 41,902,673 bp for B5-15. Molecular clock analysis estimated that H. marmoreus diverged from Termitomyces sp. approximately 59.4 million years ago during the Paleocene based on the genomic information. The two genomes showed little difference in the gene compositions related to β-Glucosidase and certain lignin degrading auxiliary enzymes. In contrast, the structures of the mating-type loci, including gene copy numbers and the transcriptional orientation of open reading frames, differed between the varieties, and it exhibited higher mating-type locus diversity. Comparative genomic analysis further indicated that the brown strain can biosynthesize melanin-like compounds using chorismate as the starting molecule, with tyrosinase acting as a key enzyme. Moreover, metabolomic profiling based on principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) revealed distinct metabolic profiles between the two varieties. Collectively, these findings improve our understanding of the genetic basis underlying the phenotypic differences between the two H. marmoreus varieties.