Submitted to: Studies in Mycology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/31/2006
Publication Date: 9/15/2006
Citation: Jaklitsch, W.M., Samuels, G.J., Dodd, S.L., Lu, B., Druzhinina, I.S. 2006. Hypocrea Rufa/Trichoderma Viride: A reassessment, and description of three closely related species with and without Warted Conidia. Studies in Mycology. 56:135-177.
Interpretive Summary: Fungi in the genus Trichoderma are effective in the biological control of a number of plant diseases including those that attack cacao trees in South America and Africa. The use of these fungi to control diseases is hindered by lack of accurate characterization of the species. In this research the one species that serves as the standard for defining the genus Trichoderma is reassessed and defined. In addition three new, related species of Trichoderma were discovered and are named, described and illustrated. Because these fungi are so small, they must be defined using characters such as the shape of their spores and how they grow as well as DNA sequences. These fungi have potential as biological control agents, thus this research will be used by plant pathologists who are working to control the diseases of cacao trees in South America and Africa.
Technical Abstract: The type species of the genus Hypocrea (Hypocreaceae, Hypocreales, Ascomycota, Fungi), H. rufa, is re-defined and epitypified using a combination of phenotype (morphology of teleomorphs and anamorphs, and characteristics in culture) and phylogenetic analyses of the translation-elongation factor 1' gene. Its anamorph, T. viride, the type species of Trichoderma, is re-described and epitypified. Eidamia viridescens is combined as Trichoderma viridescens and is recognised as one of the most morphologically and phylogenetically similar relatives of T. viride. Its teleomorph is newly described as Hypocrea viridescens. Contrary to frequent citations of H. rufa and T. viride in the literature, this species is relatively rare. Although both T. viride and T. viridescens have a wide geographic distribution, their greatest genetic diversity appears to be in Europe and North America. Hypocrea vinosa is characterised and its anamorph, T. vinosum sp. nov., is described. Conidia of T. vinosum are subglobose and warted. The new species T. gamsii is proposed. It shares eidamia-like morphology of conidiophores with T. viridescens, but it has smooth, ellipsoidal conidia that have the longest L/W ratio in Trichoderma. Trichoderma scalesiae, an endophyte of trunks of Scalesia pedunculata in the Galapagos Islands, is described as new. It only produces conidia on a low nutrient agar to which filter paper has been added. Additional phylogenetically distinct clades are recognised and provisionally delimited from the species here described. Trichoderma neokoningii, a T. koningii-like species, is described from collection made in Peru on fruit of Theobroma cacao infected with Moniliophthora roreri.