Detection and characterisation of Plum pox virus (PPV) isolates from Eastern Slovakia revealed the presence of three main viral strains.

Július Rozák,Lukáš Predajňa,Miroslav Glasa,Zdenka Gálová

doi:10.5219/315

Abstract

Plum pox virus (PPV), the agent responsible for Sharka disease, is the most important viral pathogen of stone fruit trees world-wide, having an endemic status in Slovakia. To increase knowledge of PPV diversity in Slovakia, a set of 11 isolates, originated from the eastern part of the country, was characterised. The isolates were chip-budded from their original Prunus hosts to the susceptible GF305 indicators, exhibiting the symptoms of variable severity. A genomic region encompassing the partial NIb and the hypervariable 5´terminal region of the CP gene was amplified from all 11 isolates in RT-PCR and directly sequenced. The phylogenetic analysis revealed the grouping of the 11 Slovak isolates into 3 distinct clusters, representing the PPV-M (2 isolates), D (7 isolates) and Rec strains (2 isolates). The strain affiliation of isolates was further confirmed by strain-specific RT-PCR, using which the presence of additional mixed infection by minor PPV variants was detected in 2 samples. The results further contribute to the understanding of PPV diversity in Slovakia and confirm the specificity and sensitivity of molecular approaches used for the virus strain determination.

Highlights

Plum pox virus (PPV), belonging to the genus Potyvirus, is the causal agent of Sharka, the economically most important viral disease of Prunus crops as well as wild and ornamental species (Cambra et al, 2006)
To widen the knowledge on the variability of PPV in the Eastern Slovakia, 11 isolates were sampled from various Prunus hosts showing a different response to natural PPV infection (Table 1)
PPV has been repeatedly detected in the infected GF305, the observed symptoms are likely to be caused by PPV itself

Summary

Introduction

Plum pox virus (PPV), belonging to the genus Potyvirus, is the causal agent of Sharka, the economically most important viral disease of Prunus crops (plum, apricot, peach) as well as wild and ornamental species (Cambra et al, 2006). Depending on the Prunus host and its susceptibility, the PPV-infected trees may exhibit a range of symptoms on leaves (spots, rings and mosaics, vein clearings, chlorosis and/or leaf distortions). In case of PPV, the genetic diversity might be increased by the fact that Prunus trees remain in the field for more years or decades, enabling a development of the heterogeneous viral populations (Jridi et al, 2006; Predajňa et al, 2012) or even a mixing of different strains in a single host (Candresse et al, 1998).

Results

Conclusion