48 research outputs found

    Isolates characterization of Xanthomonas sp. Associated with rice seed and differentiation of Xanthomonas oryzae strains

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    Xanthomonas oryzae pv. oryzae (Xoo) e X. oryzae pv. oryzicola (Xoc), são os agentes causais do crestamento bacteriano da folha (CBF) e da estria bacteriana da folha (EBF), respectivamente, são pragas transmitidas por sementes e sofrem restrição no comércio internacional de arroz, por estarem ausentes em muitos países e possuírem potencial de comprometer seriamente a produção de arroz. Vinte e um isolados oriundos de sementes de arroz do Uruguai e Argentina, Gram negativos, oxidase positiva, com pigmentação amarela típica do gênero Xanthomonas e positivos no ELISA para Xoo, foram caracterizados para determinar a associação destes, com X. oryzae e seus patovares. Os isolados foram caracterizados por métodos bioquímicos, biológicos e quanto à sensibilidade a antibióticos. Análises de PCR e qPCR foram realizadas para a confirmação do gênero Xanthomonas e identificação de Xoo e Xoc. A caracterização de 21 isolados de Xanthomonas sp., positivos no ELISA para Xoo, mostrou variabilidade entre os isolados e distinção de Xo.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

    Diagrammatic scale for the quantification of black spot severity in papaya leaves

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    Black spot (Asperisporium caricae) is one of the main foliar fungal diseases of papaya crops. This disease acts directly on leaves and fruits causing leaf area reduction and fruit deterioration. The quantification of diseases is a fundamental part of the disease management and control process; therefore, a scale is required to help quantify black spot disease. The objective of this work was to propose a standardized methodology to quantify black spot severity in papaya leaves. A scale was developed considering the maximum and minimum values of the disease in the field that included eight levels of severity: 0.1, 0.3, 0.6, 1.0, 2.3, 5.0, 10.0, and 20.0%. Without the aid of a scale the disease is often overestimated, with absolute errors of approximately 75%. When the scale was used, 100% of the evaluators showed improved accuracy and precision, and absolute error was reduced to the 10% range. The scale also provided good repeatability and high reproducibility. The use of the scale provided an improvement in the R2 values, with mean values of 93 and 92 in the second and third evaluations, respectively, demonstrating that the scale is useful for different aspects of the pathosystem of A. caricae, such as for determining the efficiency of fungicides, characterization of varietal resistance, construction of the disease progression curve, and estimation of damage

    I Diretrizes do Grupo de Estudos em Cardiogeriatria da Sociedade Brasileira de Cardiologia

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    O idoso apresenta características próprias na manifestação das doenças, na resposta à terapêutica e no efeito colateral dos medicamentos. Constitui um grupo de maior risco para o aparecimento das doenças degenerativas, em geral, e cardiovasculares, em particular, além de apresentar maior número de comorbidades
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