Evaluation of the Citrus tristeza virus complex occurrence in Northern Paraná State through immunological assay and SSCP

Treze isolados do Citrus tristeza virus (CTV), obtidos de pomares de laranja ‘Pêra’, da região Norte do Paraná, foram avaliados e comparados a dois isolados severos do Estado de São Paulo, por meio de I-DAS ELISA (Indirect double antibody sandwich Enzyme Linked Immunosorbent Assay) e de SSCP (Single-strand conformation polymorphism) do gene da proteína do capsídeo do vírus. Extratos de plantas de dois municípios amostrados apresentaram consideráveis valores de absorbância (A405), com os anticorpos monoclonais específicos para estirpes severas do vírus, e padrões SSCP do gene da proteína do capsídeo semelhantes aos dos isolados, oriundos do Estado de São Paulo, obtidos de plantas inoculadas com o ‘complexo Capão Bonito’. Os resultados sugerem que os pomares citrícolas da região Norte do Paraná estejam infectados por variantes severos do vírus.Thirteen Citrus tristeza virus (CTV) strains from ‘Pera’ citrus orchards, collected in Northern Paraná State, Brazil, were evaluated and compared with two severe CTV strains from São Paulo State through I-DAS ELISA (Indirect Double Antibody Sandwich Enzyme Linked Immunosorbent Assay) and SSCP (Single-strand Conformation Polymorphism) of virus capsid gene. In samples collected in two counties, high levels of absorbency (A405) were recorded, when monoclonal antibodies specific to CTV severe strains were used. In addition, SSCP patterns of these samples were identical to patterns recorded for the Capão Bonito complex from São Paulo State. These results suggest that citrus orchards of Northern Paraná State are infected with severe CTV strains