STUDIES ON THE AETIOLOGY OF APRICOT ‘VIRUELA’ DISEASE

Despite the fact that Apricot ‘Viruela’ disease (apricot pox) was described more than thirty years ago, no conclusive evidence has been reported for the identification of its causal agent.
To shed light on the aetiology of the disease we first analysed ten mature fruits from trees showing no, mild and severe symptoms of ‘viruela’ (two trees for each) to look for the presence of Apple chlorotic leaf spot virus (ACLSV), Prunus necrotic ringspot virus (PNRSV), Prune dwarf virus (PDV), Plum pox virus (PPV) and Hop stunt viroid (HSVd). From the fruits which showed mild symptoms of ‘viruela’, asymptomatic and symptomatic areas were separately extracted and analysed.
The presence of ACLSV and HSVd was detected in all the symptomatic areas of the mature fruits.
PNRSV was detected in two of the four affected trees, whereas PDV and PPV were not detected.
A large scale indexing for ACLSV and HSVd was then made with 20 ‘healthy’ mature fruits and 120 mature fruits showing symptoms of ‘viruela’. In all 120 mature fruits showing symptoms of the disease the presence of ACLSV and HSVd was recorded by non-isotopic tissue-blot hybridisation, whereas the other 20 ‘healthy’ fruits were ACLSV-free and 18 out of the 20 were positive for HSVd.
The latter result can be explained by the high incidence of HSVd in apricot trees previously observed in the Murcia Region (Cañizares et al., 1998). Our results, then, are consistent with those which suggest an association between ACLSV and apricot ‘viruela’ disease.

XVIII International Symposium on Virus and Virus-like Diseases of Temperate Fruit Crops – Top Fruit Diseases

M.C. Cañizares, F. Aparicio, K. Amari, V. Pallás

https://doi.org/10.17660/ActaHortic.2001.550.35