Soil origin, mycorrhizal plant partners and environmental factors affect the growth and development of SongRong (Tricholoma matsutake). In order to clarify the relationships of fungi–bacteria networks and various influence factors in the habitat of SongRong, we chose three collection sites with a Quercus mongolica pure forest (plot A without SongRong was used as the control sample site), Q. mongolica mixed Rhododendron dauricum (plot B) and Q. mongolica mixed with R. dauricum and Pinus densiflora (plot C). By using high-throughput sequencing, we obtained a total of 4930 fungal and 55501 bacterial amplicon sequence variants (ASVs) based on internally transcribed spacer ribosomal RNA (ITS rRNA) and 16S ribosomal RNA (16S rRNA) sequencing via the Illumina NovaSeq platform. In the habitat soil of SongRong (plot B and plot C), alpha or beta diversity and species compositions of fungi and bacteria were different from plot A. The fungal–bacterial networks follow the selection rule that few dominant genera account for the greater relative abundance. Forest types, but not the host itself, drove the fungal–bacterial networks of the forest soil, and soil physicochemical characteristics and texture affected their abundance. The abundance of Tricholoma was affected by the fungal and bacterial abundance in the habitat.

In this paper, a lightweight model—OMC-YOLO, improved based on YOLOv8n—is proposed for the automated detection and grading of oyster mushrooms. Aiming at the problems of low efficiency, high costs, and the difficult quality assurance of manual operations in traditional oyster mushroom cultivation, OMC-YOLO was improved based on the YOLOv8n model. Specifically, the model introduces deeply separable convolution (DWConv) into the backbone network, integrates the large separated convolution kernel attention mechanism (LSKA) and Slim-Neck structure into the Neck part, and adopts the DIoU loss function for optimization. The experimental results show that on the oyster mushroom dataset, the OMC-YOLO model had a higher detection effect compared to mainstream target detection models such as Faster R-CNN, SSD, YOLOv3-tiny, YOLOv5n, YOLOv6, YOLOv7-tiny, YOLOv8n, YOLOv9-gelan, YOLOv10n, etc., and that the mAP50 value reached 94.95%, which is an improvement of 2.62%. The number of parameters and the computational amount were also reduced by 26%. The model provides technical support for the automatic detection of oyster mushroom grades, which helps in realizing quality control and reducing labor costs and has positive significance for the construction of smart agriculture.

Five new Cortinarius species, C. neobalaustinus, C. pseudocamphoratus, C. subnymphatus, C. wuliangshanensis and C. yanjiensis spp. nov., are proposed based on a combination of morphological and molecular evidence. Cortinarius neobalaustinus is characterized by a very weakly hygrophanous and yellowish-brown to brown pileus and small and weakly verrucose basidiospores. Cortinarius pseudocamphoratus can be characterized by a viscid pileus, a strongly unpleasant smell, amygdaloid to somewhat ellipsoid basidiospores and lageniform to subfusiform cheilocystidia. Cortinarius subnymphatus is identified by a strongly hygrophanous pileus that is reddish-brown with a black-brown umbo, a yellowish universal veil and ellipsoid to subamygdaloid basidiospores. Cortinarius wuliangshanensis is characterized by a moderately to strongly hygrophanous, translucently striated and yellowish to reddish-brown pileus and rather weakly and moderately verrucose basidiospores. Cortinarius yanjiensis is distinguished by a weakly to moderately hygrophanous and yellowish to brown pileus and moderately to rather strongly verrucose basidiospores. The phylogenetic analyses were performed with maximum likelihood and Bayesian inference methods based on the data set of nuc rDNA ITS1-5.8S-ITS2 (ITS), D1–D2 domains of nuc 28S rDNA (28S) and RNA polymerase II second largest subunit (rpb2), and the results show that C. neobalaustinus, C. wulianghsanensis and C. yanjiensis cluster in sect. Illumini, C. pseudocamporatus belongs to sect. Camphorati and C. subnymphatus belongs to sect. Laeti. In addition, a study of basidiospores under field emission scanning electron microscopy (FESEM) was conducted. An identification key for the five new species and related species from China is also provided.

Cortinarius is an important ectomycorrhizal genus that forms a symbiotic relationship with certain trees, shrubs and herbs. Recently, we began studying Cortinarius in China and here we describe three new species of Cortinarius subg. Telamonia based on morphological and ecological characteristics, together with phylogenetic analyses. Cortinarius laccariphyllussp. nov. (section Colymbadini) is associated with broadleaf trees, with strongly hygrophanous basidiomata, special Laccaria-like lamellae and white and extremely sparse universal veil. Cortinarius neotorvussp. nov. (section Telamonia) is associated with broadleaf trees and is easily confused with C. torvus, but can be distinguished by the colour of the fresh basidiomes and the stipe usually somewhat tapering towards the base. Cortinarius subfuscoperonatussp. nov. (section Fuscoperonati) is associated with coniferous trees, with subglobose to broadly ellipsoid spores and is closely related to C. fuscoperonatus. A key to the new species and similar species in sections Colymbadini, Telamonia and Fuscoperonati is provided.

Russula rubiginosus sp. nov. (Subsect. Maculatinae) associated with Quercus mongolica is described and illustrated based on phylogenetic analyses of internal transcribed spacer (ITS) ribosomal DNA sequences and morphological evidence. This species is characterized by the rusty spots on the pileus and stipe, an acrid taste, a yellow spore print, smaller basidiospores, and abundant cystidia in pileipellis and stipitipellis. Furthermore, the morphological characteristics were described in detail and compared with R. globispora and R. subrubescens.

Russula quercina sp. nov. (sect. Polychromidia, subsect. Integroidinae) from a Quercus mongolica forest in Northeast China is described. This new species is recognized by its coral pink and glabrous pileus, slightly yellowish context, yellow basidiospore print, and abundant cystidia in stipitipellis and pileipellis. The morphological characteristics are illustrated in detail and are compared with morphologically similar species, R. integriformis, and R. laeta. Russula quercina identification is supported by molecular phylogenetic analyses based on the internal transcribed spacer regions (ITS) in the ribosomal DNA.