Evaluation of resistance to sharka (Plum pox virus) of several Prunus rootstocks

Abstract

Sharka (Plum pox virus, PPV) severely affects the production of most Prunus species in the areas affected by the disease. In this study, the resistance of 15 Prunus rootstocks to a Dideron type isolate of PPV was evaluated under controlled conditions in an insect-proof greenhouse. After four cycles of study,'GF677' almond x peach hybrid,'Myrobolan 29C plum and 'L2' cherry did not show any symptoms and were ELISA-DASI and RT-PCR negative. These were considered resistant to PPV. The rest of the rootstocks assayed showed symptoms of sharka (confirmed by ELISA-DASI or RT-PCR), although the level of susceptibility was different for each rootstock.'GF305' peach, 'Puebla de Soto' plum and 'Real Fino' apricot, were highly susceptible to PPV, showing strong sharka symptoms and being ELISA and RT-PCR positive. 'Marianna 2624' plum,'AC 9921-07' hybrid and 'CP-2' plum showed susceptibility to PPV confirmed by ELISA-DASI and RT-PCR positives.'Nemaguard' and 'Nemared' hybrids, 'Torinel' plum and 'STN2' hybrid showed an intermediate susceptibility to PPV with slight sharka symptoms and were ELISA-DASI and RT-PCR positive. Whereas, 'Montclar' peach and 'Evrica' hybrid showed moderate resistance to PPV with slight sharka symptoms and were ELISA positive but RT-PCR negative. The results open new possibilities in the search for different sources of resistance to PPV within Prunus.