Identification and pathogenicity of Macrophomina species collected from weeds in melon fields in Northeastern Brazil

"This is the peer reviewed version of the following article: Negreiros, AMP, Sales Júnior, R, León, M, et al. Identification and pathogenicity of Macrophomina species collected from weeds in melon fields in Northeastern Brazil. J Phytopathol. 2019; 167: 326 337. , which has been published in final form at https://doi.org/10.1111/jph.12801. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."[EN] In this work, a collection of 94 Macrophomina isolates obtained from roots of two weed species, Trianthema portulacastrum and Boerhavia diffusa, collected during surveys conducted during 2015 and 2016 in melon production fields in Northeastern Brazil, were characterized by using molecular techniques. Phylogenetic analysis of the EF1-alpha gene allowed the identification of 32 isolates as M. phaseolina and 62 isolates as M. pseudophaseolina. Results of a pathogenicity test performed on melon seedlings of the cv. "Gladial" revealed that all M. phaseolina isolates inoculated were able to cause disease to melon seedlings, but only some M. pseudophaseolina isolates were able to infect them. This study represents the first report of M. pseudophaseolina in both T. portulacastrum and B. diffusa weeds, which are prevalent in the main Brazilian melon producing and exporting regions. Information about the biology and epidemiology of M. pseudophaseolina is scarce because of its recent description; thus, further research is needed for a better understanding of this fungus as a potentially emerging pathogen of melon and other crops.Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior-Brazil (CAPES); Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Negreiros, AMP.; Sales Junior, R.; León Santana, M.; de Assis Melo N.J.; Michereff, S.; de Queiroz Ambrósio M.M.; De Sousa Medeiros, H.... (2019). Identification and pathogenicity of Macrophomina species collected from weeds in melon fields in Northeastern Brazil. Journal of Phytopathology. 167(6):326-337. https://doi.org/10.1111/jph.12801S326337167