RAPID DETECTION AND DIFFERENTIATION OF TOBAMOVIRUSES INFECTING L-RESISTANT GENOTYPES OF PEPPER BY RT-PCR AND RESTRICTION ANALYSIS

A procedure involving reverse transcription followed by polymerase chain reaction (RT-PCR) was developed for typing pathotypes of the tobamoviruses infecting the L-resistant genotypes of pepper. The method provides a much simpler alternative to the bioassay tests for the different Capsicum spp. genotypes previously used. Discrimination between the two pathotypes, P-1,P-2 and P-1,P-2,P-3, which cannot be differentiated by serological means, was achieved by restriction enzyme analysis of the PCR products. The assay also detects and distinguishes both pathotypes in a single mixed-infected plant. The procedure should be useful for the diagnosis and control of the disease and helpful to breeders and biotechnologists when producing and evaluating resistance in pepper plants.