While investigating macrofungi diversity in Gansu province, northwestern China, five fresh and fleshy specimens were collected, which are characterized by nearly white to buff hemispherical pileus with waved margins, a disc depressed with coral to brownish red fibrillose scales, adnate to sub-decurrent lamellae with four relatively regular rows of lamellulae, a stipe that is central, hollow, frequently straight to curved; basidiospores that are globose to subglobose, 5.0–6.0 × (3.5−) 4.0–5.0 (−5.5) μm, narrowly clavate cheilocystidia predominantly, pleurocystidia and caulocystidia not observed; and a cutis pileipellis, with hyphae slightly inflated in the KOH. The results of phylogeny analysis indicated that the species forms an independent lineage in Phyllotopsidaceae based on the ITS (ITS5/ITS4) and nLSU (LR0R/LR7) dataset. Molecular clock analyses suggested the common ancestor of Neotricholomopsis emerged later than upper Cretaceous with a mean crown age of 229.36 Mya (95% highest posterior density of 129.63–343.08 Mya). These five specimens were described as an unreported taxon based on the phylogeny analysis combined with morphological examination and ecological and geographical distribution. Detailed descriptions, illustrations, and phylogenetic trees to demonstrate the placement of this species and discussions with its related species are provided.

The genus Diaporthe comprises a functionally diverse group of fungi, inhabiting plant tissues as pathogens, endophytes, and saprobes. Many species cause significant diseases in economically and ecologically important woody plants. Despite extensive research on the taxonomy and phylogeny of Diaporthe over the past two decades, species delineation remains challenging due to the high morphological plasticity among the more than 1,000 described taxa. In practice, molecular phylogenetic divergence has become the primary criterion for species delimitation, as morphological characters often fail to resolve species boundaries. In this study, we employed an integrative taxonomic approach combining multi-locus phylogeny with morphological characterization to investigate Diaporthe isolates associated with leaf spot diseases on Fagaceae , a dominant tree family in Chinese forests. Our investigation resolved eight distinct lineages, including five novel species described herein: namely D. castanopsidicola , D. changjiangensis , D. cyclobalanopsidicola , D. liangxii , and D. lithocarpicola from Guangdong and Hainan Provinces, China. These findings significantly contribute to resolving the cryptic diversity of Diaporthe and expand our understanding of the fungal communities driving foliar diseases in Fagaceae .

The genera Pseudoclavibacter and ‘Zimmermannella’ (a later homotypic synonym of Pseudoclavibacter) are both described to accommodate Brevibacterium helvolum in 2004. The genus Gulosibacter, published in the same year, also shows a close similarity to the 16S rRNA gene sequence of genus ‘Zimmermannella’. To clarify the phylogenetic relationship of these genera, phylogenomic analysis has been performed on the representatives of three genera and five isolates from the poplar tree (poplar isolates) in the family Microbacteriaceae. The phylogenetic analyses based on genome and 16S rRNA gene sequences suggest that P. albus and ‘P. triregionum’ should belong to a novel genus in family Microbacteriaceae, which is supported by the results of AAI analysis. In the Phylogenomic tree, the five poplar isolates, P. caeni, and P. soli are grouped together to form one distinct clade from Pseudoclavibacter and Gulosibacter and other genera in the family Microbacteriaceae, suggesting that they should belong to a novel genus within the family Microbacteriaceae. The five poplar isolates are divided into two distinct groups from P. caeni and P. soli in the phylogenomic tree, suggesting that they should belong to two novel species, which is also supported by ANI analysis, phenotypic, and chemotaxonomic characteristics. Based on the data obtained, the following taxonomic proposals are made: (1) classification of the poplar isolates as Yuansilingia populi gen. nov. sp. nov. (type strain PZ6^T = CFCC 11306^T = LMG 31539^T) and Yuansilingia affinipopuli sp. nov. (type strain is 13-3^T = CFCC 11305^T = LMG 42092^T); (2) reclassification of Pseudoclavibacter caeni and Pseudoclavibacter soli as Yuansilingia caeni comb. nov. (type strain is KCTC 19773^T = JCM 16921^T = CFCC 10881^T), Yuansilingia soli comb. nov. (type strain is KCTC 19255^T = JCM 15058^T = CFCC 10840^T); (3) reclassification of P. albus as the type species of a novel genus, Urinibacter gen. nov., as Urinibacter albus comb. nov. (type strain IAM 14724^T = NBRC 15616^T = TISTR 1510^T = CFCC 11178^T), Pseudoclavibacter triregionum as Urinibacter triregionum comb. nov. (type strain is 125703-2019^T (=R-76471^T = LMG 31777^T = CCUG 74796^T).