First report of the occurrence of bacterial leaf streak of corn caused by Xanthomonas vasicola pv. vasculorum in Brazil.
In April 2018, diseased maize leaf samples were collected in commercial fields in the western region of Parana, Brazil. The leaves with initial symptoms of the disease had translucent yellow to brown narrow linear lesions with irregular margins, confined to the interveinal spaces. Older symptoms on highly susceptible maize hybrids had coalescing long lesions of dark coloration, reaching large extension along the leaf blade. Preliminary examinations did not show any structure of fungi but revealed the presence of bacterial ooze. The causal pathogen was isolated and identified as Xanthomonas axonopodis pv. vasculorum based on biochemical, physiological, molecular and pathogenicity analyses. The sequences of the bacterial strains were deposited in GenBank (accession nos. MH497007 and MH497008). This is thought to be the the first report of the occurrence of bacterial leaf streak of maize caused by Xanthomonas axonopodis pv. vasculorum in Brazil.