Resumo

HERNANDEZ-RODRIGUEZ, Lester; PEREZ LOPEZ, Edel; LUIS PANTOJA, Maritza  e  PENA BARZAGA, Inés. Evaluation of two techniques for the molecular diagnosis of rickettsia associated to papaya bunchy top disease in Cuba. Rev. Protección Veg. [online]. 2014, vol.29, n.2, pp. 82-93. ISSN 1010-2752.

The aim of this study was to develop a technique based on non radioactive nucleic acid hybridization for the diagnosis of rickettsia-PBT bacterium associated to the papaya bunchy top disease (NASH-PBT), and to evaluate its use compared with the conventional PCR. The optimized NASH-PBT method allowed the specific detection of 15 pg of sdhA gen DNA of rickettsia-PBT. The validation parameters in the evaluation of 141 controls previously characterized by PCR evidenced the reliability of the technique, showing diagnosis sensitivity (DS) of 97.2% and diagnosis specificity (DE) of 98.5%. The simultaneous analysis by the NASH-PBT and conventional PCR (PCR-PBT) of 179 samples recovered from commercial fields, mostly of the western region of Cuba, evidenced the presence of rickettsia-PBT in 118 plants. The parameters of validations of PCR-PBT and NASH-PBT in the analysis of these samples were 89% and 75% for DS and 96% and 98% for DE, respectively. Despite the lower sensibility value showed respect to NASH-PBT PCR-PBT, its use for genetic improvement programs or surveys in epidemiological studies of this pathogen is realiable.

Palavras-chave : papaya bunchy top; rickettsia; hybridization; papayo; sensitivity; specificity.

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