First report of Plum pox virus in Finland
In July 2014, leaf symptoms consisting of yellowish blotches and ring patterns were detected in a plum tree (Prunus domestica cv. ‘Renklod Mitshurinskij’) in a nursery in Eastern Finland. This tree, originating from Russia, had been planted for more than 10 years and at the time of these observations, it was used as a mother tree. Laboratory analysis (RT-PCR, sequencing) confirmed the presence of Plum pox virus (Potyvirus, PPV – EPPO A2 List) and the strain was characterized as PPV-D. Following this initial detection, 91 additional samples were collected (July-September 2014) from nurseries, orchards, garden centres, private gardens, collections, and tested for PPV by DAS-ELISA. Six samples from orchards and private gardens gave positive results and all could be traced back to the originally infected mother tree. No other nursery or cultivar was found to be affected by PPV. This is the first time that PPV is reported from Finland. Considering that this PPV outbreak is limited to a single mother tree and its progeny and that all infected plants have been destroyed, it is thought that eradication of PPV from Finland will be possible. However, as the virus is transmitted locally by a number of aphid species in a non-persistent manner and infected plants can remain asymptomatic for several months, specific surveys will be continued in 2015.
The situation of Plum pox virus in Finland can be described as follows: Transient, first found in 2014 in a single mother tree and its progeny, under eradication.
Sources
Santala J, Soukainen M (2015) First report of Plum pox virus on plum in Finland. Bulletin OEPP/EPPO Bulletin 45(early view) DOI:10.1111/epp.12199