Taxonomy and phylogeny of five novel Trichoderma (Hypocreaceae, Hypocreales) species isolated from decaying wood in China

A taxonomic study was conducted on Trichoderma species isolated from decaying wood in China. As a result, five novel species, T. flavobritdaniae , T. foliatum , T. fulviclavum , T. liaoningense , and T. parvostromatum , were identified, described in detail, and illustrated based on morphological characteristics and molecular data inferred from sequences of the second largest subunit of RNA polymerase II ( rpb 2) and the translation elongation factor 1-alpha ( tef 1-α). Among the five new species, T. flavobritdaniae , T. fulviclavum , and T. parvostromatum exhibit both asexual and sexual morphs, whereas T. foliatum and T. liaoningense are currently known only from their asexual morphs. Notably, T. fulviclavum produces clavate stromata but does not cluster with clavate-stromatic species traditionally assigned to the Viride clade. Phylogenetic analyses recovered all five taxa as well-supported, distinct lineages assigned to the Longibrachiatum, Harzianum, Psychrophilum, Semiorbis, and Brevicompactum clades. The discovery of these new species from China improves the understanding of Trichoderma diversity and biogeography and provides genetic resources with potential agricultural and industrial applications.