Xylella fastidiosa detected for the first time on olive trees in Brazil
At the end of 2014, symptoms of leaf scorch were observed on olive trees (Olea europaea) growing in the Mantiqueira mountain range region, located in the states of Minas Gerais and São Paulo, Brazil. These symptoms resembled those caused by Xylella fastidiosa (EPPO A1 List) on olive trees in Southern Italy and Argentina. Diseased trees were found in olive orchards of Maria da Fé (Minas Gerais) and São Bento do Sapucaí (São Paulo) which are approximately 130 km apart. Samples (branches, twigs and leaves) were collected from symptomatic and asymptomatic trees. Laboratory studies (morphology, PCR tests, sequencing, phylogenetic analysis) confirmed the presence of Xylella fastidiosa subsp. pauca in 8 symptomatic samples (out of 9). This study also revealed some differences between the sequence type of the bacterium found in Brazil (ST16) with the one found in Italy (ST53). Considering the proximity of coffee plantations to olive orchards in the affected areas of the Mantiqueira mountain range region, it is suspected that X. fastidiosa subsp. pauca has been introduced in olive trees from coffee plants by leafhopper vectors. It is noted that further pathogenicity tests with different strains of X. fastidiosa subsp. pauca are under way in Brazil, and it is hoped that these will provide more information about the susceptibility of olive trees to a broad spectrum of strains. This is the first time that X. fastidiosa is reported on olive trees in Brazil.
Sources
Della Coletta-Filho H, Francisco CS, Lopes JRS, de Oliveira AF, da Silva LF (2016) First report of olive leaf scorch in Brazil, associated with Xylella fastidiosa subsp. pauca. Phytopathologia Mediterranea 55(1), 130-135.