Occurrence and variability of Potato yellow vein virus in three departments of Colombia

Potato yellow vein virus (PYVV) causes dramatic yield reductions in potatoes in Andean countries, particularly Colombia. We tested 250 potato leaf samples suspectedly infected with PYVV from three Colombian Departments and assessed genetic diversity in the coat protein gene of 18 representative isolates by RT-PCR-RFLP analysis with HinfI. RFLP profiles revealed that 80% of these isolates had an identical restrictotype while the remaining isolates comprised two further restrictotypes or mixtures of two restrictotypes which included the predominant type and one other type. In samples from the Cundinamarca and Antioquia Departments, all three restrictotypes were detected including mixed infections, whereas in samples from the Narino Department only the predominant restrictotype was detected.