Sensitivity of peach cultivars against a Dideron isolate of Plum pox virus

Abstract: Sharka disease, caused by Plum pox virus (PPV), is one of the most significant limiting factors for Prunus production worldwide, and the cultivation of resistant cultivars is the only definitive solution to this problem. In this study, 40 cultivated peach cultivars with different origins, chill requirements and fruit type were evaluated against a PPV Dideron-type isolate in controlled conditions in greenhouse for three evaluation cycles. Cultivars were grafted onto PPV infected ‘GF305′ rootstocks and, in each cycle, the presence of symptoms on leaves was scored and ELISA and RT-PCR was applied to check the presence of PPV on rootstocks and cultivars. The results showed the resistance of ‘Catherine’ to this strain, for this cultivar never showed sharka symptoms and was ELISA and RT-PCR negative. Some cultivars without symptoms but ELISA or PCR positive were tolerant to PPV. Most cultivars were sensitive, and showed symptoms of sharka or were ELISA or RT-PCR positive. In these cultivars, different degrees of symptom expression among the three cycles and between replications of each cultivar were observed. [Copyright &y& Elsevier]