Resumo

HERNANDEZ, Alexander et al. Molecular characterization of 12 isolates of Trichoderma spp. using RAPD and rDNA-ITS. Bioagro [online]. 2013, vol.25, n.3, pp.167-174. ISSN 1316-3361.

Genetic variability among isolates of the bio-controller Trichoderma associated with different crops is an important topic of study. The purpose of this research was to characterize ten isolates of Trichoderma spp. and two commercial strains associated to garlic crop, using RAPD and rDNA-ITS. Isolates were obtained from sclerotia, rhizosphere, soil and bulbs affected by white rot (Sclerotium cepivorum). Genetic variability was analyzed by classification and management techniques from the Jaccard distance ratios. Results from RAPD analyses were similar to those conducted by rDNA-ITS markers. It was found that the isolates belonging to the species T. harzianum, T. koningiopsis, T. atroviride, T. pseudokoninngii and T. longibrachiatum were grouped in relation to genetic diversity without a clear relationship in terms of geographical origin. The range of genetic distance among the different isolates was 0.11-0.87 for RAPD, and 0.08-0.62 for rDNA-ITS. The isolates Ar-01, Ar-02 and Ta-01 were classified along with the commercial strains and could be good controllers and inducers of resistance in garlic plants affected by white rot.

Palavras-chave : T. harzianum; T. koningiopsis; T. atroviride; T. pseudokoningii; T. longibrachiatum.

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