Determination of synergistic interactions between Plum pox virus and 'Candidatus Phytoplasma prunorum' in infected peach trees
This assessment of the interaction between Plum pox virus (PPV) and European stone fruit yellows (ESFY; caused by 'Candidatus Phytoplasma prunorum') infections in two peach cultivars, 'Symphony' and 'Royal Glory', took place in the years 2012-2013. Trees showing symptoms of PPV were artificially infected with ESFY and, conversely, trees with ESFY were infected with PPV (the D strain). Trees infected with only one of the two pathogens acted as controls. Synergistic and antagonistic interactions were visually assessed using a four-point scoring system for the principal symptoms characteristic of each pathogen, accompanied by quantitative measurements of the pathogenic organisms present in leaf tissue (using nested PCR and measuring the titre in DAS-ELISA). PPV-infected trees inoculated with ESFY showed reduced levels of PPV symptoms, but ESFY-infected trees inoculated with PPV displayed enhanced symptoms of both infections, in what might be called a synergistic manner. Laboratory measurements showed that the leaves of ESFY-inoculated trees had average relative concentrations of PPV of 3.3×10-1 ('Symphony') and 2.5×10-1 ('Royal Glory') and average relative concentrations of the ESFY phytoplasma of 24,303 copies μL-1 DNA ('Symphony') and 268,000 copies μL-1 DNA ('Royal Glory'). The leaves of PPV-inoculated trees had an average relative concentration of PPV of 4.4×10-1 and an average concentration of ESFY phytoplasma of 32,849 copies μL-1 DNA.
Horsáková, J., Nečasová, J. and Nečas, T. 2017. Determination of synergistic interactions between Plum pox virus and 'Candidatus Phytoplasma prunorum' in infected peach trees. Acta Hort. (ISHS) 1163:45-52
ESFY, PPV, ELISA, PCR, Prunus persica L., synergy