TESTING OF PLUM GERMPLASM TO PLUM POX VIRUS SUSCEPTIBILITY

An orchard of plum germplasm was established during autumn 1990 in a space isolation using one-year-old trees on Myrobalan rootstock, 2 trees per cultivar and spacing 6 x 4 m.
A choice of cultivars for the experiment was based on previous negative ELISA tests for Plum Pox Virus (PPV). All trees were indexed by ELISA for Prune Dwarf Virus (PDV), Prune Necrotic Ringspot Virus (PNRSV) and PPV during beginning of the growing season 1991. In August 1991 all trees were inoculated by a strong strain by PPV by budding 3 buds from a contaminated ‘Domestic Prune’ tree on every stem.
In the following year 1992 visible symptoms of PPV on leaves were evaluated and new ELISA tests were done.
Both evaluated cultivars and shoots from budded ‘Domestic Prune’ (a source of PPV) were studied.

After these artificial inoculations 69,5 % of trees were infected by PPV. The most successful transmission of PPV was found on those cultivars which had been virus free.
A coefficient of association was highest in the case of combination of PNRSV and PPV. A negative relationship between a new infection of PPV and previous contamination by PNRSV was highly significant according to X² tests.
Other relations between PPV and PDV or between PPV and PDV + PNRSV (complex) were not significant.
Despite of a short time duration, the experiment indicates a possibility of mutual

V International Symposium on Plum and Prune Genetic, Breeding and Pomology

F. Paprstein, J. Blazek, R. Karesova

https://doi.org/10.17660/ActaHortic.1994.359.21