Lentinula edodes is a tetrapolar basidiomycete with two haploid nuclei in each cell during most of their life cycle. Understanding the two haploid nuclei genome structures and their interactions on growth and fruiting body development has significant practical implications, especially for commercial cultivars. In this study, we isolated and assembled the two haploid genomes from a commercial strain of L. edodes using Illumina, HiFi, and Hi-C technologies. The total genome lengths were 50.93 Mb and 49.80 Mb for the two monokaryons SP3 and SP30, respectively, with each assembled into 10 chromosomes with 99.63% and 98.91% anchoring rates, respectively, for contigs more than 100 Kb. Genome comparisons suggest that two haploid nuclei likely derived from distinct genetic ancestries, with ~30% of their genomes being unique or non-syntenic. Consistent with a tetrapolar mating system, the two mating-type loci A (matA) and B (matB) of L. edodes were found located on two different chromosomes. However, we identified a new but incomplete homeodomain (HD) sublocus at ~2.8 Mb from matA in both monokaryons. Our study provides a solid foundation for investigating the relationships among cultivars and between cultivars and wild strains and for studying how two genetically divergent nuclei coordinate to regulate fruiting body formation in L. edodes.

Trichoderma is known worldwide as biocontrol agents of plant diseases, producers of enzymes and antibiotics, and competitive contaminants of edible fungi. In this investigation of contaminated substrates of edible fungi from North China, 39 strains belonging to 10 Trichoderma species isolated from four kinds of edible fungi were obtained, and three novel species belonging to the Harzianum clade were isolated from the contaminated substrates of Auricularia heimuer and Pholiota adipose. They were recognized based on integrated studies of phenotypic features, culture characteristics, and molecular analyses of RNA polymerase II subunit B and translation elongation factor 1-α genes. Trichoderma auriculariae was strongly supported as a separate lineage and differed from T. vermifimicola due to its larger conidia. Trichoderma miyunense was closely related to T. ganodermatigerum but differed due to its smaller conidia and higher optimum mycelial growth temperature. As a separate lineage, T. pholiotae was distinct from T. guizhouense and T. pseudoasiaticum due to its higher optimum mycelial growth temperature and larger conidia. This study extends the understanding of Trichoderma spp. contaminating substrates of edible fungi and updates knowledge of species diversity in the group.

Casing soil is a key step in the production of Oudemansiella raphanipes. Bacterial community in casing soil plays key roles in the growth and development of edible fungi. However, a knowledge gap remains regarding the bacterial community shifts in casing soil before and after the cultivation of O. raphanipes (CSBACO). Casing soil samples before and after the cultivation of O. raphanipes (CSBC and CSAC) were collected and examined by high-throughput 16S rRNA gene sequencing technology. Actinobacteria, Proteobacteria, Chloroflexi, and Acidobacteria were dominant phyla in casing soil of O. raphanipes, which accounted for 77.32% of the total abundance. After the cultivation of O. raphanipes, the alpha diversity of bacterial community and the relative abundance of some beneficial genera such as Marmoricola, Nocardioides, Sphingomonas, and Streptomyces decreased, while that of bacteria belonging to the candidate class MB-A2-108 tolerant to adverse environment significantly increased. Meanwhile, physicochemical properties of casing soil changed significantly in CSBACO. Soil ammonium nitrogen and organic matter greatly decreased in CSAC and they mainly influenced bacterial community before the cultivation of O. raphanipes. In contrast, available potassium and pH significantly increased in CSAC and mainly affected bacterial community after the cultivation of O. raphanipes. Furthermore, the relative abundance of bacteria with the function of amino acid and lipid metabolism decreased, while that of bacteria functions related to parasites and pathogens increased, which further revealed the significance of bacterial community in casing soil. Diversity, composition, and the potential function of bacterial community shifted dramatically in CSBACO. The results deepen the understanding of the bacterial community and its microecological mechanism in casing soil of O. raphanipes.

Introduction: Verticillium wilt is the most devastating soil-borne disease affecting Cotinus coggygria in the progress of urban landscape construction in China.Methods: To assess the variability of the rhizosphere-associated soil microbiome in response to Verticillium wilt occurrence, we investigated the microbial diversity, taxonomic composition, biomarker species, and co-occurrence network of the rhizosphere-associated soil in Verticillium wilt-affected C. coggygria using Illumina sequencing.Results: The alpha diversity indices of the rhizosphere bacteria in Verticillium wilt-affected plants showed no significant variability compared with those in healthy plants, except for a moderate increase in the Shannon and Invsimpson indices, while the fungal alpha diversity indices were significantly decreased. The abundance of certain dominant or crucial microbial taxa, such as Arthrobacter, Bacillus, Streptomyces, and Trichoderma, displayed significant variations among different soil samples. The bacterial and fungal community structures exhibited distinct variability, as evidenced by the Bray–Curtis dissimilarity matrices. Co-occurrence networks unveiled intricate interactions within the microbial community of Verticillium wilt-affected C. coggygria, with greater edge numbers and higher network density. The phenomenon was more evident in the fungal community, showing increased positive interaction, which may be associated with the aggravation of Verticillium wilt with the aid of Fusarium. The proportions of bacteria involved in membrane transport and second metabolite biosynthesis functions were significantly enriched in the diseased rhizosphere soil samples.Discussion: These findings suggested that healthy C. coggygria harbored an obviously higher abundance of beneficial microbial consortia, such as Bacillus, while Verticillium wilt-affected plants may recruit antagonistic members such as Streptomyces in response to Verticillium dahliae infection. This study provides a theoretical basis for understanding the soil micro-ecological mechanism of Verticillium wilt occurrence, which may be helpful in the prevention and control of the disease in C. coggygria from the microbiome perspective.

Auricularia cornea var. Li. is a natural mutation strain of A. cornea which has been preferred by consumers for its white colour, good taste and pharmacological properties (Rebecca et al. 2020). In...