Phylogeny and variability ofColletotrichum truncatumassociated with soybean anthracnose in Brazil

Autor: Álvaro M. R. Almeida, Flávia Rogério, Nelson Sidnei Massola, C. D. S. Seixas, Carlos Augusto Dórea Bragança, Marina Coan Goldoni Barbieri, Maisa Ciampi-Guillardi
Rok vydání: 2017
Předmět:
Zdroj: Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual)
Universidade de São Paulo (USP)
instacron:USP
ISSN: 1364-5072
DOI: 10.1111/jam.13346
Popis: Aims Fungal diseases are among the main factors limiting high yields of soybean crop. Colletotrichum isolates from soybean plants with anthracnose symptoms were studied from different regions and time periods in Brazil using molecular, morphological and pathogenic analyses. Methods and Results Bayesian phylogenetic inference of GAPDH, HIS3 and ITS-5.8S rDNA sequences, the morphologies of colony and conidia and inoculation tests on seeds and seedlings were performed. All isolates were clustered only with Colletotrichum truncatum species in three well-separated clusters. Intraspecific genetic diversity revealed 27 distinct haplotypes in 51 fungal isolates; some of which were identical to C. truncatum sequences from other regions around the world, while others were related to alternative hosts. Conidia were falcate, hyaline, unicellular and aseptate, with variable dimensions, formed in acervuli. Despite being pathogenic to seedlings by both inoculation methods, variation was observed in the aggressiveness of the tested isolates, which was not correlated to genetic variation. Conclusion The identification of C. truncatum in the sampled isolates evidenced it being the only causal agent of soybean anthracnose in Brazil until 2007, with relevant genetic, morphological and pathogenic variability as well as a broad geographical origin. The wide distribution of the predominant C. truncatum haplotype indicated the existence of a highly efficient mechanism of pathogen dispersal over long distances, reinforcing the role of seeds as the primary source of disease inoculum. Significance and Impact of the Study The characterization and distribution of Colletotrichum species in soybean-producing regions in Brazil is fundamental for understanding the disease epidemiology and for ensuring effective control strategies against anthracnose. This article is protected by copyright. All rights reserved.
Databáze: OpenAIRE
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