Isolates characterization of Xanthomonas sp. associated with rice seed and differentiation of Xanthomonas oryzae strains/Caracterizacao de isolados de Xanthomonas sp. associados a sementes de arroz e diferenciacao de estirpes de Xanthomonas oryzae

• Published in: Ciência rural 2015-12, p.2099
• Main Authors: de Souza, Jr., Ismail Teodoro, Santos, Mauren de Oliveira, de Oliveira, Andreia Mara Rotta, de Moraes, Marcelo Gravina, Duarte, Valmir
• Format: Article
• Language: Spanish
• ISSN: 0103-8478
• DOI: 10.1590/0103-8478cr20141164

Xanthomonas oryzae pv. oryzae (Xoo) and X. oryzae pv. oryzicola (Xoc), causal agents of bacterial leaf blight (BLB) and bacterial leaf streak (BLS), respectively, are pests transmitted by seeds and suffer restriction on international rice trade, because are absent in many countries and have potential to compromise seriously rice production. Twenty-one isolates from rice seeds from Uruguay and Argentina, Gram negative, oxidase positive, with typical yellow pigmentation of genus Xanthomonas and positive in ELISA for Xoo, were characterized to determine their association with X. oryze pathovars. Isolates were characterized by biochemical, biological and antibiogram methods. PCR and qPCR analyzes were performed to confirm genus Xanthomonas and identification of Xoo and Xoc. Characterization of 21 Xanthomonas sp. isolates positive on ELISA to Xoo, showed variability among isolates and distinction of Xo. Key words: phytosanitary security, false-postive, molecular methods, Oryza sativa. Xanthomonas oryzae pv. oryzae (Xoo) e X. oryzae pv. oryzicola (Xoc), sao os agentes causais do crestamento bacteriano da folha (CBF) e da estria bacteriana da folha (EBF), respectivamente, sao pragas transmitidas por sementes e sofrem restricao no comercio internacional de arroz, por estarem ausentes em muitos paises e possuirem potencial de comprometer seriamente a producao de arroz. Vinte e um isolados oriundos de sementes de arroz do Uruguai e Argentina, Gram negativos, oxidase positiva, com pigmentacao amarela tipica do genero Xanthomonas e positivos no ELISA para Xoo, foram caracterizados para determinar a associacao destes, com X. oryzae e seus patovares. Os isolados foram caracterizados por metodos bioquimicos, biologicos e quanto a sensibilidade a antibioticos. Analises de PCR e qPCR foram realizadas para a confirmacao do genero Xanthomonas e identificacao de Xoo e Xoc. A caracterizacao de 21 isolados de Xanthomonas sp., positivos no ELISA para Xoo, mostrou variabilidade entre os isolados e distincao de Xo. Palavras-chave: defesa fitossanitaria, falso-positivos, metodos moleculares, Oryza sativa.