Evaluation of Apricot selections for tollerance to plum pox virus (PPV)

The following apricot progenies from a breeding program for resistance to Plum pox virus (PPV) were analysed for susceptibility to several strains of the virus: ‘Cricot’ × ‘Stark Early Orange’, ‘Goldrich’ × NJA 53, ‘Harcot’ × ‘Reale d’Imola’, ‘Boreale’ × ‘Harcot’, ‘Harcot’ × ‘Tirzii di Bucuresti’ and ‘Reale d’Imola’ × ‘Harcot’. Each of the 99 seedlings obtained was grafted onto five Prunus persica (L.) Batsch. ‘GF 305’ which were then inoculated by chip-budding with a PPV-M isolate. All plants were grown in a greenhouse at 22-24 °C. The evaluation was done by observing symptoms on both ‘GF 305’ and apricot, and by ELISA. Most of the seedlings showed symptoms on apricot, except for six seedlings which were symptomless, negative in ELISA and in top-grafted ‘GF 305’. The resistant seedlings (four from ‘Cricot’ × ‘Stark Early Orange’; one from ‘Goldrich’ × NJA 53 and one from ‘Harcot’ × ‘Reale d’Imola’), remained symptomless and ELISA negative also when inoculated with PPV-D and PPV-EA strains.