Hypocrea/Trichoderma species with pachybasium-like conidiophores: teleomorphs for T. minutisporum and T. polysporum and their newly discovered relatives.

We describe or redescribe species of Hypocrea/Trichoderma (Ascomycetes, Hypocreales) having hyaline ascospores and pachybasium-like conidiophores. Teleomorphs are reported for Trichoderma minutisporum (Hypocrea minutispora sp. nov.) and T. polysporum (H. pachybasioides). Hypocrea pilulifera/T. piluliferum is redescribed. Trichoderma croceum is synonymized with T. polysporum. The new species H. parapilulifera, H. stellata and H. lacuwombatensis are described. All of these species fall within the morphological concept of Trichoderma sect. Pachybasium and within the phylogenetic group pachybasium B5 of Kullnig-Gradinger et al (2002). Parsimony analysis of nucleotide sequences from three unlinked loci-ITS1 and 2, endochitinase (ech42) and translation elongation factor 1-alpha (tef1)-detects two distinct phylogenetic lineages within the group pachybasium B5. One comprises H. pachybasioides/T. polysporum, H. pilulifera/T. piluliferum, H. parapilulifera and H. stellata; this group, the "polysporum" lineage, is characterized by having conidia that are white in mass and is the only lineage within Hypocrea characterized by such conidia. The second group includes the green conidial T. minutisporum and H. lacuwombatensis. The partition homogeneity test reveals significant recombination within the "polysporum" lineage but not within the "minutisporum" lineage.