Four new species of Trichoderma with hyaline ascospores from southwest China

Abstract

Collections of Trichoderma were made from southwest China and examined. Four new species producing hyaline ascospores, T. fructicola, T. medogense, T. palidulum and T. virgineum, were found, and are described and illustrated. Their phylogenetic positions were allocated based on sequence analyses of the combined RNA polymerase II subunit b and translation elongation factor 1 alpha genes. Trichoderma fructicola, appearing as a lone lineage among hyaline-ascospored groups, is diagnostic by cortical tissues of textura epidermoidea, remarkable colour change of peridium in KOH, and verticillium- to trichoderma-like conidiophores. As a sister of T. voglmayrii, T. medogenseis similar to T. voglmayrii in having yellow-brown to purplish red stromata and trichoderma-like conidiophores, but differs in apapillate ostioles, subcortical tissues of textura intricata, narrow phialides, andsmaller conidia. Trichoderma palidulumis located in the Viride clade andis distinct from its alliesin stroma and colony morphology. Trichoderma virgineum is closely associated with T. henanense and T. odoratum. The three species are similar in having yellowish stromata, monomorphic ascospores, white colonies produced on three standard media, simple-branched conidiophores, and hyaline conidia for which anew clade is proposed. Morphological distinctions and sequence divergences between the new species and their close relatives are discussed.