Esca proper and Botryosphaeria dieback are among the most widespread Grapevine trunk diseases (GTDs), characterized by similar decline symptoms. In the present work, chronic, apoplexy and death symptoms were analysed separately in four vineyards and four different cultivars, on more than 1,000 vines per cultivar, taking into account ten-year annual surveys. The cumulative incidence of plants with chronic symptoms (CHR) reached high values on 'Sauvignon Blanc' (81.9 %), 'Cabernet Sauvignon' (79.4 %) and 'Cannonau' (66.5 %), but it was low on 'Merlot' (25.1 %). 'Sauvignon Blanc' showed the highest cumulative incidence of apoplectic events (23.1 %) and dead cordons (49.2 %), while 'Cannonau' had the greatest number of dead plants (28.8 %). In each symptom category, incidence among cultivars differed significantly according to chi(2) test at P <= 0.05. Annual incidence of foliar symptoms fluctuated over ten years (ranging from 0.9-9.5 % in 'Merlot' to 6.3-59.1 % in 'Cabernet Sauvignon'), mostly with regard to CHR. On average, every year only 33.9 % of plants showing CHR had expressed symptoms in the previous year, while 48.6 % did not show symptoms the following year. Conversely, most of the plants exhibiting apoplexy or death were symptomatic the previous year. According to Tuckey HSD test (P <= 0.05) 'Merlot' had the highest incidence of plants showing CHR symptoms for the first time (72.1 %) and of apparently recovered plants (76.3 %), while 'Cabernet Sauvignon' exhibited the highest incidence of plants showing CHR symptoms also the previous year (50.0 %). The 'Cabernet Sauvignon' attitude to show chronic symptoms with a certain continuity was also confirmed by the low incidence of plants with hidden symptoms (lack of symptoms in previously symptomatic vines). On the contrary, the incidence of acute symptoms (apoplectic events and dead plants) was quite low on 'Cabernet Sauvignon'. The present study confirms that GTD incidence is influenced by cultivar. All the cultivars assessed were susceptible, but with differences in intensity, type (chronic or acute) and fluctuation of symptoms. It cannot be excluded, however, that besides the genotype also external factors, as the vigour conferred by the type of soil or the combination with the rootstock, may have influenced the results.

HomePlant DiseaseVol. 102, No. 10First Report of Grapevine Asteroid Mosaic-Associated Virus Infecting Grapevines (Vitis vinifera) in Italy PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of Grapevine Asteroid Mosaic-Associated Virus Infecting Grapevines (Vitis vinifera) in ItalyA. Porceddu, M. Sanna, V. A. Prota, N. Schianchi, L. Mercenaro, G. Nieddu, and S. CamioloA. Porceddu, M. Sanna, V. A. Prota, N. Schianchi, L. Mercenaro, G. Nieddu, and S. Camiolo†Corresponding author: S. Camiolo; E-mail: E-mail Address: scamiolo@uniss.ithttp://orcid.org/0000-0002-8874-9993AffiliationsAuthors and Affiliations A. Porceddu M. Sanna V. A. Prota N. Schianchi L. Mercenaro G. Nieddu S. Camiolo † , Dipartimento di Agraria, Università degli Studi di Sassari, 07100, Sassari, Italy. Published Online:3 Aug 2018https://doi.org/10.1094/PDIS-03-18-0460-PDNAboutSections ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat Asteroid mosaic, a disease of the grapevine fleck complex characterized by starlike spots on the foliage of several cultivars of Vitis vinifera and clearing of primary and secondary veins on V. rupestris, was originally described in California (Hewitt 1954). An isometric virus, named grapevine asteroid mosaic-associated virus (GAMaV), was partially characterized from original Californian sources (Abou Ghanem-Sabanadzovic et al. 2003) and reported in Canada (Xiao and Meng 2016), Uruguay (Jo et al. 2015), and more recently in France (Candresse et al. 2017). In the summer of 2016, 48 grapevine berry samples (24 V. vinifera ‘Cannonau’ and 24 V. vinifera ‘Cabernet Sauvignon’), were collected between veraison and harvest in Alghero (northwest Sardinian Island, 40.650638, 8.241534) and their gene expression investigated by RNAseq. For each sample, total RNA was extracted with the RNeasy Plant mini kit (Qiagen), reverse transcribed, and cDNA libraries were prepared using the TrueSeq RNA kit (Illumina) according to the manufacturer’s instructions. Sequencing was performed on an Illumina Miseq system and produced an average of 40,842,896 paired-end reads (2 × 101 nt). The obtained reads were screened against the virus genome database (ftp://ftp.ncbi.nlm.nih.gov/refseq/release/viral/) and aligned to the large portions of the GAMaV genome for four samples of cultivar Cannonau. The presence of the virus was confirmed by reverse transcription polymerase chain reaction using primers GAMaV-F3 (5′-ATCTCGCAGCCCAACCTCTG-3′) and GAMaV-R3 (5′-CATGATGACGGCTTGGGTCTT-3′) (Candresse et al. 2017). Detected polymorphisms (GATK pipeline) indicated the coexistence of two distinct virus variants. De novo assembly of the produced reads (by the usage of the software Spades) followed by manual curation of the obtained scaffolds led to the reconstruction of the partial genome of such variants (two scaffolds of 6,204 nt) that were deposited to the NCBI nucleotide database with the accession numbers MH061348 and MH061349. Both sequences covered 92% of the reference genome NC_031692.1 (Vargas-Asencio et al. 2017) with a percentage of identity of 92%, and the reciprocal homology proved to be 97%. Such observations demonstrate the presence of GAMaV in Italy. Noteworthy, although the vineyard was composed of both Cannonau and Cabernet Sauvignon vines, only four samples from the cultivar Cannonau showed the presence of the virus. Although we do not provide conclusive data on a different susceptibility of the used grapevine genotypes, we suggest that clone selection may have played a primary role. No detectable symptoms were observed in any of the infected vines, thus supporting the hypothesis that GAMaV may be largely latent or semilatent as previously reported (Martelli 2014). Analysis of the RNAseq experiments showed that the four infected plants were also coinfected by grapevine fleck virus, grapevine rupestris stem pitting-associated virus, grapevine leafroll-associated virus 2, grapevine yellow speckle viroid 1, and grapevine Syrah virus 1.References:Abou Ghanem-Sabanadzovic, N., et al. 2003. Virus Genes 27:11. https://doi.org/10.1023/A:1025164200412 Crossref, ISI, Google ScholarCandresse, T., et al. 2017. Plant Dis. 101:6. https://doi.org/10.1094/PDIS-01-17-0012-PDN Google ScholarHewitt, W. B. 1954. Bull. Calif. Dept. Agric. 43:47. Google ScholarJo, Y., et al. 2015. Sci. Rep. 5:15841. https://doi.org/10.1038/srep15841 Crossref, ISI, Google ScholarMartelli, G. P. 2014. J. Plant Pathol. 96:1S. ISI, Google ScholarVargas-Asencio, J., et al. 2017. Virus Res. 227:82. https://doi.org/10.1016/j.virusres.2016.10.001 Crossref, ISI, Google ScholarXiao, H., and Meng, B. 2016. Plant Dis. 100:2175. https://doi.org/10.1094/PDIS-03-16-0413-PDN Link, ISI, Google ScholarDetailsFiguresLiterature CitedRelated Vol. 102, No. 10 October 2018SubscribeISSN:0191-2917e-ISSN:1943-7692 Metrics Article History Issue Date: 28 Sep 2018Published: 3 Aug 2018First Look: 24 Apr 2018Accepted: 21 Apr 2018 Page: 2049 Information© 2018 The American Phytopathological SocietyCited byVirome of Grapevine Germplasm from the Anapa Ampelographic Collection (Russia)15 June 2022 | Viruses, Vol. 14, No. 6Grapevine fleck virus (fleck of grapevine)CABI Compendium, Vol. CABI CompendiumGrapevine asteroid mosaic-associated virusCABI Compendium, Vol. CABI CompendiumGrapevine Syrah virus 1CABI Compendium, Vol. CABI CompendiumGrapevine yellow speckle viroid 1CABI Compendium, Vol. CABI CompendiumGrapevine Asteroid Mosaic-Associated Virus is Resident and Prevalent in Wild, Noncultivated Grapevine of New York StateJeremy R. Thompson, Annika L. Gomez, Aisha Younas, Juliana González-Tobón, Alex Cha, and Keith L. Perry11 March 2021 | Plant Disease, Vol. 105, No. 4First Report of Grapevine Asteroid Mosaic Associated Virus in Grapevine in SpainF. Morán, C. Canales, A. Olmos, and A. B. Ruiz-García8 December 2020 | Plant Disease, Vol. 105, No. 2Vitis vinifera (Grape)6 June 2020

Grapevine Pinot gris virus (GPGV) was identified in several grapevine cultivars, particularly in cv. 'Vermentino' showing leaf mottling and deformation, in the Sardinia and Lazio regions of Italy. The majority of GPGV-infected cultivars were asymptomatic, but the virus was not detected in samples from vineyards older than 10 years and/or planted with local cultivars, confirming the recent introduction of the virus in these two regions likely through the distribution and use of infected propagation material. As in reports from other regions, the high incidence of GPGV in asymptomatic vines is creating challenges with regard to control.

Research Note Grapevine trichovirus A (GVA) and grapevine trichovirus B (GVB) were successfully transferred with bulk transmission trials under controlled conditions, from infected grapevines to herbaceous hosts by Pseudococcus affinis MASK., a pseudococcid mealybug that may attack grapevines. P. affinis is the fourth mealybug species capable of vectoring GVA and GVB, confirming that transmission by mealybugs of grapevine trichoviruses may not be species-specific.

Sanitary selection and certification of olive cultivars require sensitive diagnostic methods and effective sanitation protocols. Although much attention has been paid in the past few years to the development of diagnostic tools for reliable virus identification, the need to define a common and standardized diagnostic protocol led to the implementation of a ring test among nine Italian diagnostic laboratories. A one‐step RT‐PCR protocol and different primer sets, targeting the most common olive viruses covered by phytosanitary rules, were tested in each laboratory, using the same batch of positive and healthy controls as well as the same amplification conditions and reaction components. The one‐step RT‐PCR, performed using several specific primer sets, was able efficiently to detect the target viruses in all laboratories. Furthermore, a one‐step RT‐PCR protocol was used successfully for the first time for detection of Tobacco necrosis virus (TNV) and Olive mild mosaic virus (OMMV). Results showed that all target viruses were not uniformly distributed in the canopy, and that at least two subsets of samples must be collected from each plant. This standardized protocol is now being used to produce nuclear stocks for 70 different Italian olive cultivars, in the framework of the national project OLVIVA, which involves 25 national research institutions.

A study was made on the recovery genotypes local grapevine with the aim to conserve them and to evaluate their health status and thus to improve the quality of the propagation material. Clone accessions of 61 vines were grafted and placed in a germoplasma field. The varieties that were considered enologically valuable were subjected to sanitary selection. Some vines showed indubitable healthy qualities, and should be immediately evaluated from an economical point view and then certificated. Possible sanitation treatments were also evaluated, with the aim of extending the number clone accessions to be included in experimental trials to access their yield .

Epidemiological surveys were performed in Northern Sardinia (Italy) in a 10-year-old vineyard affected by "Bois noir" disease. Samples collected between May and October 2003 from chlorotic and stunted weeds belonging to 14 different taxonomic groups were indexed molecularly for detection of phytoplasmas. Nested polymerase chain reaction (PCR) assays using primers specific for the phytoplasma 16SrDNA gene showed three of six Calendula arvensis, one of two Solanum nigrum, and one of seven Chenopodium spp. assayed positive. Restriction fragment length polymorphism analyses and sequencing of amplified 16SrDNA fragments identified a putative phytoplasma in the ribosomal subgroup 16SrII-E. Further characterization of the rps3 gene, coding a ribosomal protein, confirmed the identification. However. the weeds and leafhopper species collected in the vineyard tested negative by PCR assays for the Stolbur phytoplasma, the causal agent of "Bois noir". This is the first report of a phytoplasma of the 16SrII-E subgroup infecting C. arvensis, S. nigrum, and Chenopodium spp.