Almond (Prunus dulcis L.) - not a natural host of Plum pox virus in the Czech Republic
Plum pox virus (PPV) is the most important virus infecting stone-fruit trees (Prunus spp.). Almond (Prunus dulcis L.) is identified as a host plant, but the symptomatology is uncertain, and it is unclear whether almond can be infected naturally or only via PPV-infected rootstock. To evaluate the current situation in the Czech Republic and determine the importance of almond in PPV spread, a survey was conducted in 2015-2016. In six locations, almond orchards and landscape trees, samples were collected from both symptomatic and non-symptomatic almond trees, as well as from symptomatic plums and apricots as positive controls. Screening was carried out for the presence of PPV and other viruses known to infect almonds, using an imunochromatographic test, RT-PCR and PDO-ntRT-PCR analyses. PPV was not detected in any of the analysed almond trees. Symptom occurrence was not a reliable indicator of PPV infections in almonds. Although some almond trees showed intensive symptoms (vein clearing, yellow mosaics and chlorotic rings), the presence of PPV was not confirmed by RT-PCR. Apple chlorotic leaf spot virus (ACLSV), the known causal agent of 'pseudopox' disease, and also Prunus necrotic ringspot virus (PNRSV) and Prune dwarf virus (PDV) were detected in symptomatic almond trees. Our study indicates that, even when grown under high PPV-D infection pressure, over many years, these almond trees are not naturally infected by PPV. In this case, almond trees do not appear to represent a potential risk as a reservoir for the present isolates of PPV or to play a role in virus spread under the studied conditions.
Šafáøová, D., Neoralová, V., James, D. and Navrátil, M. 2017. Almond (Prunus dulcis L.) - not a natural host of Plum pox virus in the Czech Republic. Acta Hort. (ISHS) 1163:123-128
almond, RT-PCR, PPV-D, PNRSV, PDV, ACLSV