Seven wood-inhabiting new species of the genus Trichoderma (Fungi Ascomycota) in Viride clade

摘要

More than 200 recent collections of Trichoderma from China were examined and 16 species belonging to the Viride clade were identified based on integrated studies of phenotypic and molecular data. Among them, seven wood-inhabiting new species, T. albofulvopsis, T. densum, T. laevisporum, T. sinokoningii, T. sparsum, T. sphaerosporum and T. subviride, are found. They form trichoderma- to verticillium-like conidiophores, lageniform to subulate phialides and globose to ellipsoidal conidia, but vary greatly in colony features, growth rates, and sizes of phialides and conidia. To explore their taxonomic positions, the phylogenetic tree including all the known species of the Viride clade is constructed based on sequence analyses of the combined RNA polymerase II subunit b and translation elongation factor 1 alpha exon genes. Our results indicated that the seven new species were well-located in the Koningii, Rogersonii and Neorufum subclades as well as a few independent terminal branches. They are clearly distinguishable from any existing species. Morphological distinctions and sequence divergences between the new species and their close relatives were discussed.