Chemical products induce resistance to Xanthomonas perforans in tomato

• Autor(a) principal: Itako,Adriana Terumi
• Data de Publicação: 2015
• Outros Autores: Tolentino Júnior,João Batista, Silva Júnior,Tadeu Antônio Fernandes da, Soman,José Marcelo, Maringoni,Antonio Carlos
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Brazilian Journal of Microbiology
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822015000300701
• topic: Solanum lycopersicum; bacterial spot; control; enzymes

The bacterial spot of tomato, caused by Xanthomonas spp., is a very important disease, especially in the hot and humid periods of the year. The chemical control of the disease has not been very effective for a number of reasons. This study aimed to evaluate, under greenhouse conditions, the efficacy of leaf-spraying chemicals (acibenzolar-S-methyl (ASM) (0.025 g.L−1), fluazinam (0.25 g.L−1), pyraclostrobin (0.08 g.L−1), pyraclostrobin + methiran (0.02 g.L−1 + 2.2 g.L−1), copper oxychloride (1.50 g.L−1), mancozeb + copper oxychloride (0.88 g.L−1 + 0.60 g.L−1), and oxytetracycline (0.40 g.L−1)) on control of bacterial spot. Tomatoes Santa Clara and Gisele cultivars were pulverized 3 days before inoculation with Xanthomonas perforans. The production of enzymes associated with resistance induction (peroxidase, polyphenol oxidase, phenylalanine ammonia-lyase, β-1,3-glucanase, and protease) was quantified from leaf samples collected 24 hours before and 24 hours after chemical spraying and at 1, 2, 4, 6, and 8 days after bacterial inoculation. All products tested controlled bacterial spot, but only ASM, pyraclostrobin, and pyraclostrobin + metiram increased the production of peroxidase in the leaves of the two tomato cultivars, and increased the production of polyphenol oxidase and β-1,3-glucanase in the Santa Clara cultivar.