A new species, Chloridium paucisetosum, was isolated from soil in Guizhou Province, China. The species is distinguished from other Chloridium species by its cylindrical or lageniform conidiogenous cells producing obovoid or ellipsoidal conidia without mucoid appendages, and apical branched conidiophores. Phylogenetic analysis based on combined ITS and LSU sequence data showed that C. paucisetosum formed a monophyletic clade and clearly separated from other Chloridium species. It is compared with other similar species and their phylogenetic relationships are discussed. Morphology and phylogenetic analyses support the introduction of the new species C. paucisetosum. In addition, a previously described species Phialocephala humicola is synonymized under the genus Chloridium.

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Rosa roxburghii Tratt. is widely applied in food, cosmetics, and traditional medicine, and has been demonstrated to possess diverse bioactivities. Plant endophytic fungi are important microbial resources with great potential for application in many fields. They not only establish mutualistic symbiosis with host plants but also produce a variety of bioactive compounds. Therefore, in the present study, endophytic fungi were isolated from R. roxburghii, the diversity and antimicrobial activities were evaluated. As a result, 242 strains of endophytic Sordariomycetes were successfully isolated. Multigene phylogenetic analyses showed that these isolates included eight orders, 19 families, 33 genera. The dominant genera were Diaporthe (31.4%), Fusarium (14.4%), Chaetomium (7.9%), Dactylonectria (7.0%), Graphium (4.5%), Colletotrichum (4.1%), and Clonostachys (4.1%). For different tissues of R. roxburghii, alpha diversity analysis revealed that the diversity of fungal communities decreased in the order of root, fruit, stem, flower, leaf, and seed, and Clonostachys and Dactylonectria exhibited obvious tissue specificity. Meanwhile, functional annotation of 33 genera indicated that some fungi have multitrophic lifestyles combining endophytic, pathogenic, and saprophytic behavior. Additionally, antimicrobial activities of endophytic Sordariomycetes against Lasiodiplodia theobromae, Botryosphaeria dothidea, Colletotrichum capsici, Pyricularia oryzae, Rhizoctonia solani, Fusarium oxysporum, Pseudomonas syringae, Pantoea agglomerans, Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa were screened. Dual culture test assays showed that there were 40 different endophytic species with strong inhibition of at least one or moderate inhibition of two or more against the 12 tested strains. The results from the filter paper diffusion method suggested that extracellular metabolites may be more advantageous than intracellular metabolites in the development of antimicrobial agents. Eleven isolates with good activities were screened. In particular, Hypomontagnella monticulosa HGUP194009 and Nigrospora sphaerica HGUP191020 have shown promise in both broad-spectrum and intensity. Finally, some fungi that commonly cause disease have been observed to have beneficial biological activities as endophytic fungi. In conclusion, this study showed the species composition, alpha diversity, and lifestyle diversity of endophytic Sordariomycetes from R. roxburghii and demonstrated these isolates are potential sources for exploring antimicrobial agents.

Rosa roxburghii Tratt., a deciduous shrub of the family Rosaceae, is usually used as food and medicinal materials and also cultivated as an ornamental. Plant endophytic fungi are a large class of microbial resources not fully researched, with great potential applications. Two strains of Ascodesmis and Talaromyces were isolated during a survey of biodiversity on endophytic fungi of R. roxburghii in China. Multigene phylogenetic analyses showed that each of the two fungi formed a distinct lineage and separated from known congeneric species and they are proposed as two novel taxa. Ascodesmis rosicola sp. nov. usually has one or two conspicuous simple or branched ridges extending to the majority of the ascospore surface and remarkably small asci, distinguishing it from the previously-described species in the genus Ascodesmis. Talaromyces rosarhiza sp. nov., of the section Talaromyces, is closely related to T. francoae. It differs from the latter by having both monoverticillate and biverticillate conidiophores, while those of T. francoae are biverticillate. Both novel endophytes are illustrated and described.

A new species, Melnikomyces longisporum sp. nov. was isolated from forest litter in Guizhou Province, China. Phylogenetic analysis based on a combined nuclear ribosomal markers (SSU, ITS, and LSU) and protein coding genes (ACT1, TUB2, and TEF1-α) sequence data indicated that this strain belonged to the genus Melnikomyces but it constituted a distinct lineage and represented herein as a novel taxon. Morphological examination showed that it can be distinguished from known Melnikomyces species by its longer branched conidiophores, and longer verruculose conidia.