Molecular detection of olive viruses*

Abstract

Olive hosts 13 viruses belonging in seven different genera. Additional non‐mechanically transmissible viruses probably infect olive in nature, as suggested by the widespread occurrence of double‐stranded RNAs (dsRNAs) in trees from which no viruses can be recovered by manual inoculation. Because sanitary selection appears to be the only measure for restraining virus dissemination through propagating material, detection methods are needed which are more sensitive and reliable than those currently available (biological and serological). The following molecular techniques have therefore been used and their efficiency compared: (1) dsRNA analysis; (2) dot‐blot hybridization with digoxigenin‐labelled riboprobes in separate reactions or in mixture; and (3) reverse transcription‐polymerase chain reaction (RT‐PCR). It was found that: (1) dsRNAs were detected in 210 out of 286 olive accessions (73.4%) coming from six different Italian regions; (2) one‐step RT‐PCR yielded much better results using TNA extracts than crude sap; and (3) dot‐blot hybridization of denatured dsRNAs with digoxigenin‐labelled virus‐specific riboprobes was the most reliable detection method available.

Effect ofCucumber mosaic virus(CMV) infection on antineoplastic alkaloids from periwinkle (Catharanthus roseusL.) cultured in the Mecca region and resistance induction by plant-growth-promoting rhizobacteria (PGPR)

“…The detection of CMV by RT-PCR was carried out using a set of specific primers, CMV-s 5'-TAACCTCCCAGTTCT-CACCGT-3' and CMV-a 5'-CCATCACCTTAGCTTCCATGT-3' for the CMV-RdRp gene, whose nucleotide sequences and use-conditions have previously been described [24]. Briefly, 2.5 mL of reverse-transcribed TNA mixtures were subjected to amplification with the addition of 2.5 mL of 10 £ Taq polymerase buffer (Promega Corporation, USA), with a final concentration of 1.5 mmol/L MgCl 2 for a total volume of 25 mL.…”

“…The CMV inocula were prepared from CMV-infected top periwinkle leaves that yielded a positive reaction on ELISA. The periwinkle seedlings were conserved in a greenhouse at [24][25][26][27] C. ELISA was used in addition to symptom observation to check for the presence of the virus. Seedling pots were placed in a completely randomized block design with three seedlings per pot, three pots per replicate and three replicates per treatment, giving a total of 27 seedlings per treatment.…”

Phytosanitary Certification

“…Concerning viruses, RT-PCR assay has proved to be the most rapid, sensitive and reliable technique for detecting an RNA target in infected plants, and in recent years, different protocols have been developed for olive viruses detection (Grieco et al, 2000;Bertolini et al, 2001aBertolini et al, , 2003Pantaleo et al, 2001;Faggioli et al, 2002Faggioli et al, , 2005. Recently, a one step RT-PCR protocol has been set up and validated in an inter-laboratory ring test (Loconsole et al, 2010) for the diagnosis of the eight most important olive viruses.…”

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

“…• 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). …”

“…• 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).…”