Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 8/27/2001
Publication Date: N/A
Technical Abstract: Trichoderma sect. Trichoderma is one of five sections of Trichoderma. It includes three species viz. T. viride, T. atroviride and T. koningii. Species which are ubiquitous and frequently cited in biocontrol and ecology literature. Recent evidence from the comparison of sequences of the ITS regions of rDNA indicated that they hardly differ from each other and might even be considered one species. This is supported by the fact that the T. viride phenotype was found in two ITS sequence types. Moreover, their Hypocrea teleomorphs all fit the H. rufa species phenotype and are, therefore, morphologically similar and possibly indistinguishable. For this taxonomic study of T. sect. Trichoderma we sequenced the ITS rDNA and the translation elongation factor (tef 1-alpha) genes of 180 Trichoderma/Hypocrea putative members of T. sect. Trichoderma and of the paraphyletic T. sect. Pachybasium. Comparison of sequence data from the ITS-1 region revealed a strongly supported, but unresolved, clade consisting of T. asperellum (T. sect Pachybasium) and T. hamatum (T. sect Pachybasium), plus the T. viride, T. atroviride, and T. koningii. Preliminary results from the examination of tef1-alpha sequences revealed the resolution of more species, in particular T. atrovirirde. However, the T. koningii and to a lesser extent the T. viride phenotypes remained dispersed among diverse genotypes. To conclude, results to date indicate that there are more than the three currently recognized species within T. sect Trichoderma.