Journal of Plant Pathology Archive

Abstract:

Olive (Olea europea L.) is cultivated in Lebanon on a surface of ca.53.600 ha, accounting for 43% of the area given over to perennial crops (Anonymous, 2010). Olive trees are affected by a number of virus and virus-like agents that persist in propagating material, with which they can be transmitted and disseminated (Martelli, 2011). Twelve trees of cv. Airouni, which is one of the most important cultivars grown in the country, were sampled in northern Lebanon and assayed for determining their sanitary status, in view of their possible use by nurseries for propagation. No symptoms of putative viral origin were observed in the surveyed orchards. Leaf samples were tested by RT-PCR to assess the presence of viruses commonly found in olive, i.e. Arabis mosaic virus (ArMV), Cherry leaf roll virus (CLRV), Cucumber mosaic virus (CMV), Olive latent ringspot virus (OLRSV), Olive latent virus 1 (OLV-1), Olive latent virus 2 (OLV-2), Olive leaf yellowing-associated virus (OLYaV) and Strawberry latent ringspot virus (SLRSV), using the protocol and the sets of specific primers reported by Grieco et al. (2000). Results showed that CLRV, OLV-1, OLV-2 and OLYaV are present in nine trees, whereas ArMV and SLRV were not found. Two samples were positive for CMV and OLRSV, yielding the expected amplified products of 513 bp and 492 bp, respectively. Both these viruses were mechanically transmitted to herbaceous hosts (Cucumis sativus and Chenopodium quinoa, respectively) and their presence in these hosts was ascertained by RT-PCR. One of the trees proved free from all viruses and may constitute a source of virus-tested material for propagation. To our knowledge, this is the first report of CMV and OLRSV in olive in Lebanon.