Tomato spotted wilt virus associated with lettuce dieback in Bekaa Valley, Lebanon

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First Report of 'Candidatus Phytoplasma phoenicium' on Almond in Southern Italy

In spring 2017, phytoplasma suspected symptoms were reported on 25% of 15-year-old almond plants, cultivars Filippo Ceo and Genco grafted onto GF677, in a commercial orchard (20 ha) located at Grottaglie, Apulia (southeast Italy). Among the symptoms, development of many axillary buds with small and yellowish leaves, and witches' brooms developing from the trunk, were the most frequent, followed by leaf rosetting, proliferation of slender shoots, tree decline, and dieback

Removal of viruses from Lebanese fig varieties using tissue culture and thermotherapy

Two Lebanese fig accessions of local varieties (Biadi and Aswad), infected by Fig leaf mottle-associated virus 1 (FLMaV-1), Fig leaf mottle-associated virus 2 (FLMaV-2) and Fig mosaic virus (FMV), were subjected to tissue culture and thermotherapy for producing virus-free plant material. The virus status of all progeny explants was assayed by RT-PCR using viruses-specific primers. The shoot tip culture technique was reliable for elimination of from 60 to 100% of fig viruses. However, stem cutting culture coupled with thermotherapy was the most effective for shoot regeneration (40% of reactive explants), while elimination of the three viruses was possible even though with lower rates of removal (from zero to 81%) were achieved. This study has indicated that FLMaV-2 is more susceptible to thermotherapy than FLMaV-1 and FMV

Landscape restoration due to Xylella fastidiosa invasion in Italy: Assessing the hypothetical public’s preferences

Since 2013, the olive landscapes have gradually degenerated due to the spread and establishment of Xylella fastidiosa subsp. pauca (hereafter Xf) in Apulia, southern Italy. From 2013 to 2019, a total of approximately 54,000 hectares of olive orchards in the south of this region have been seriously damaged, and their restoration will progressively regenerate the economic, social, cultural and environmental nonmarket benefits. Since there is a willingness to restore the affected landscape in the best interest of the local citizens, this research aims to predict their preference heterogeneity and willingness to pay (WTP) to improve this landscape and continue research and experimentation in relation to Olive Quick Decline Syndrome Disease by the bacterium. For this purpose, a choice experiment method is used. The social field survey includes a representative sample of 683 respondents in three major cities (Foggia, Bari and Lecce) of Apulia region. The results reveal that for the local citizens interviewed, the most appreciated olive landscape services are cultural heritage and aesthetic values. In addition, the findings revealed citizens’ positive appreciation of improving the damaged olive landscape, while respondents are not willing to pay a premium for research. The results show that the average value that Apulians are willing to pay for landscape restoration is about 5.7 million of € per year. Further, this research has implications for land use planners in the study area, which faces issues of harmful pathogen management and land revival

Xylella fastidiosa invasion of new countries in Europe, the Middle East and North Africa: Ranking the potential exposure scenarios

After the recent high-impact European outbreaks of Xylella fastidiosa (Xf), a xylem-limited plant pathogenic bacterium native to the Americas, this research aims to rank the risks of potential entry, establishment and spread of Xf in new countries across Europe, the Middle East and North Africa. A novel risk-ranking technique is developed, based on combining entry risk drivers (imported plants, direct flights and ferry connections) with risk factors related to establishment and spread (presence of potential insect vectors, vulnerable economic crops, alternative hosts and climate suitability) of this pathogen. This reveals that western European countries have the highest risk for entry, but that the Mediterranean basin runs the highest risk for establishment and spread of Xf. Lebanon in particular has the highest level of risk for Xf dispersal within its suitable territory. Countries without current outbreaks combining high risks of Xf arrival and establishment are mainly in the Mediterranean basin: Turkey is at the highest level of risk, followed by Greece, Morocco and Tunisia, which are ranked at the high level. The ranking model also confirms the vulnerability, in terms of invasion by Xf, of southern European countries (Italy, Portugal and Spain) in which the pathogen has already been reported. High summer temperatures in these southern countries are likely to be the significant determinant for the overall invasion process, while northern European countries have a high level risk for the arrival of the pathogen, but relatively low summer temperatures may limit establishment and spread of major outbreaks. In general, our study provides a useful approach for mapping and comparing risks of invasive non-native species and emerging pathogens between countries, which could be useful for regional horizon scanning and phytosanitary and biosecurity management

Surveys of potato-growing areas and surface water in Lebanon for potato brown and ring rot pathogens.

Field surveys were carried out over three growing seasons (2013\u20132015), in the main potato growing areas of Lebanon, to assess the occurrence of potato brown rot caused by Ralstonia solanacearum and potato ring rot caused by Clavibacter michiganensis subsp. sepedonicus. A total of 232 potato samples were collected from Bekaa valley and 145 samples from Akkar plain, which are the largest Lebanese areas cropped with potatoes. Composite samples of 200 potato tubers were randomly collected from each field, following procedures laid down in EU legislation. Twelve potato demonstration fields were established in Akkar plain and designed for potato export to European markets: these were also surveyed using the same strategy. Furthermore, a network of 40 sampling sites in Bekaa and 19 sites in Akkar was established to collect surface water. GPS coordinates of potato fields and water sampling sites were recorded to map specific sampling points using Geographic Information System. All samples gave negative results for R. solanacearum and C. michiganensis subsp. sepedonicus in potatoes and R. solanacearum in water, as indicated using the official EU methods for detection and diagnosis for these pathogens. A monitoring system for R. solanacearum and C. michiganensis subsp. michiganensis has been set up in Lebanon. This will increase the phytosanitary quality of potatoes and provide access to broader international markets

Identification of new 16SrIX subgroups, -F and -G, among ‘Candidatus Phytoplasma phoenicium’ strains infecting almond, peach and nectarine in Lebanon

Almond witches’-broom is a lethal almond disease associated with ‘Candidatus Phytoplasma phoenicium’, subgroups 16SrIX-B and -D. In Lebanon, where the disease was first reported, analogous diseases affecting peach and nectarine were recently associated with presence of ‘Ca. P. phoenicium’. In the present study, genetic diversity among 24 ‘Ca. P. phoenicium’ strains infecting almond, peach and nectarine plants in diverse geographic regions of Lebanon was investigated by virtual restriction fragment length polymorphism (RFLP) analysis of 16S rDNA nucleotide sequences. Calculation of virtual restriction similarity coefficients revealed the presence of two new subgroups, -F and -G, in group 16SrIX that were confirmed by real RFLP analyses. Obtained results open new opportunities for in-depth studies of the distribution of ‘Ca. P. phoenicium’ strains in plant hosts and insect vector populations from different geographic areas of Lebanon

Ricerche su virus filamentosi della vite: a) Indagine sul Trichovirus A (GVA), b) Descrizione del nuovo closterovirus 7 associato all'accartocciamento fogliare (GLRaV-7)

Dottorato di ricerca in protezione delle colture. 8. ciclo. A.a. 1992-95. Relatore V. Savino. Correlatori G. P. Martelli e R. GarauConsiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7, Rome; Biblioteca Nazionale Centrale - P.za Cavalleggeri, 1, Florence / CNR - Consiglio Nazionale delle RichercheSIGLEITItal