Detection of Olive-Infecting Viruses in the Mediterranean Basin

Abstract

Olive (Olea europaea) is host of 13 different viruses but, it is possible that other viruses, which are either non mechanically transmissible or occur in low concentration in plant tissues, are present in nature. This likelihood is supported by the widespread occurrence of double-stranded RNAs (dsRNAs) in plants negative to biological tests. As very little information is available on the geographical distribution of olive-infecting, investigations were conducted for gathering information on the prevalence and distribution of olive viruses in the Mediterranean basin based on the presence of double stranded RNA (dsRNA). A total of 527 samples were collected throughout the surveys covering 10 countries and 83 locations. Out of 286 tested samples collected from 6 Italian regions, 210 (73.4%) were dsRNA positive, whereas the average of viral infections in the Mediterranean basin was 64.5%. Molecular hybridisation tests, on 25 % of dsRNA-positive samples collected in Apulia, revealed the presence of the three nepoviruses (ArMV, CLRV and SLRSV), OLYaV and OLV-1.

On the presence and distribution of olive viruses in Lebanon

“…Out of 55 samples analysed, 17 (34%) contained dsRNAs, a figure lower than that (70%) obtained with previous tests on 30 samples (Saponari et al ., 2002).…”

“…All these viruses (OLYaV, OLV-1, CLRV, SLRSV and ArMV) occur in Lebanon, but their level of infection is, on average, lower than that recorded from other Mediterranean countries (Martelli, 1999;Saponari et al ., 2002). Worthy of special mention is the detection of ArMV, a nepovirus latent in olive, which can be very damaging to many important crops like stone fruits and grapevine.…”

A degenerate pair of primers for simultaneous detection of four alpha- and betanecroviruses

“…In general, considerable levels of viral infection have been detected in many regions, including Portugal. In this country, extensive field surveys have revealed Olive latent virus 1 (OLV-1), Olive mild mosaic virus (OMMV) and Tobacco necrosis virus D (TNV-D) as predominant, reaching infection levels of 31%, with OMMV the most abundant virus (Saponari et al, 2002;Varanda et al, 2006Varanda et al, , 2010El Air et al, 2011). These viruses have several natural hosts.…”

Inventory and world geographical distribution of the olive tree (Olea europaea L.) diseases caused by viruses, bacteria and phytoplasma

“…• Cucumber mosaic virus (CMV): Croitia Luigi et al, 2011;; Italy Saponari et al, 2002aBellini et al, 2002;Grieco et al, 2000;Maretti and Gallitelli, 1985; Savino and Gallitelli, 1983a); Spain Bertolini et al, , 2001bGrieco et al, 2000); Portugal Felix and Clara, 2006;Félix et al, 2002;Grieco et al, 2000;Leitao et al, 1999; da Clara Henriques, 1994;Rei et al, 1993); Tunisia (Boulila, 2016;; Egypt Youssef et al, 2010); California ; Albania Çġfçġ and Serçe, 2014; Beler and Açikgöz, 2005;; Syria ; Algeria ; Australia ; France (Rwahnih et al, 2011); Cyprus ; Israel ; Morocco ; Palestine ; Greece ; Lebanon (Choueiri et al, 2015).…”

“…• Olive latent virus-2 (OLV-2): Croitia Luigi et al, 2011;; Italy Bellini et al, 2002;Saponari et al, 2002aPantaleo et al, 2001;Grieco et al, 1996bGrieco et al, , 2002Grieco et al, , 2000Castellano et al, 1987;Maretti and Gallitelli, 1985;Savino et al, 1984; Corte et al., 1961); Spain ; Syria ; Lebanon ; Tunisia (Boulila, 2016;; Egypt ; Greece ; Turkey Çġfçġ and Serçe, 2014;; Albania Luigi et al, 2009); Portugal Henriques et al, 1992Henriques et al, , 1990). …”