Trichoderma communities of the winter wheat rhizosphere in the Pannonian Plain

A total of 116 Trichoderma strains were isolated from roots of winter wheat from test holes of five agricultural fields in the Pannonian Plain. The identity of the strains was examined based on the sequence analysis of the internal transcribed spacer (ITS) region by TrichOKEY 2.0. The examined wheat field rhizosphere samples could be characterized with a remarkable biodiversity. The 11 taxa detected in the samples were T. harzianum, T. pleuroticola, T. tomentosum/T. cerinum, T. virens, T. rossicum, T. spirale, T. brevicompactum, T. atroviride, T. gamsii, T. koningiopsis/T. ovalisporum and T. longibrachiatum/H. orientalis. The most frequently isolated species was T. harzianum with 41 isolates representing a series of known ITS genotypes as well as 2 genotypes that were firstly obtained during this study. Both T. virens (31 isolates) and T. atroviride (9 isolates) could be classified into 2 ITS-genotypes, one of them being identical with that of the ex-type strains in the cases of both species. Ten isolates proved to belong to 2 genotypes of T. rossicum, one of them has not been found so far. The remaining 7 species were isolated with a lower frequency. Several species could be characterized with well-defined isoenzyme patterns during celluloseacetate electrophoresis