The effectiveness of hypersensitivity resistance of Prunus domestica ‘Jojo’ and P. domestica × P. cerasifera ‘Docera^® 6′ against a broad range of Plum pox virus isolates

Hypersensitivity resistance of European plum (Prunus domestica L.) against the Plum pox virus (PPV) is, for the moment, the only naturally occurring resistance mechanism that prevents plum orchards from economic damages caused by the sharka disease.
The resistance of the genotypes investigated is derived from the cultivar ‘Ortenauer’. Budsticks of the European plum cultivar ‘Jojo’ and the interspecific P. domestica × P. cerasifera hybrid ‘Docera 6’ (Dhypres 6) were inoculated with several PPV isolates of PPV strains PPV-D, PPV-Rec, and PPV-M and, additionally, a PPV isolate called PPV isolate Herrenberg which is not yet assigned to the known PPV strains.
For inoculation, the double grafting method with a PPV infected interstem and a P. cerasifera rootstock was used.
Typical symptoms of hypersensitivity resistance were observed in all cases except plants inoculated with PPV isolate Herrenberg.
The PPV isolate Herrenberg is not known to occur in nature but only in PPV collections at the Technical University of Munich and Bavarian Centre of Pomology and Fruit Breeding, Germany.
Therefore it has to be concluded that the hypersensitivity resistance derived from P. domestica cultivar ‘Ortenauer’ is effective against all isolates occurring under natural inoculation conditions tested up to now.

XI International Symposium on Plum and Prune Genetics, Breeding and Pomology

J. Hadersdorfer, F. Dittrich, M. Neumüller

Plum pox virus, European plum, durable resistance

https://doi.org/10.17660/ActaHortic.2019.1260.15