عنوان مقاله [English]
نویسنده [English]چکیده [English]
Fungi belonging to genus Trichoderma are well known for their effectiveness in the biological control of different plant pathogenic fungi, inducing systemic resistance in crops and for promoting plant growth. Phylogeny of 81 Trichoderma isolates (with emphasis on some biocontrol strains) belonging to six species obtained from paddy fields in Mazandaran province, was studied by partial sequence analyses of the translation elongation factor 1-α (tef1α) gene. Data were analyzed by Neighbor-Joining, Maximum Parsimony and Minimum Evolution methods. For each analysis, one consensus tree was used out of all generated phylograms. Phylogenetic trees of the 41 Trichoderma isolates inferred by all methods and programs were similar. Results showed that 14 tef1α haplotypes can be recognized for T. harzianum (the most frequent species in rice fields) isolates grouped into five clades. Therefore, this complex species presented the highest intraspecific diversity when compared to other species in this study. In contrast, only two haplotypes were recognized for T. virens, the second most prevalent species. Furthermore, sequence analyses revealed three and two haplotypes for T. atroviride and T. hamatum, respectively. Results indicated that biological control strains represented various haplotypes and placed in different clades along with other native isolates. Consequently, a specific tef1α haplotype related to antagonism could not be distinguished. In addition, there was no correlation between tef1α haplotype and the geographic location and thus different species and haplotypes were isolated from the same sampling sites.