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Electron microscopy of extracts from diseased Polygonum convolvulus plants from Piedmont (Italy) revealed particles with the morphological features of a tospovirus. Sequencing of the full-length small (S) and medium (M) genome segments indicated that the virus is a member of a new Tospovirus species provisionally named Polygonum ringspot virus. A feature distinguishing it from members of other Tospovirus species was the presence of a very short intergenic region on the S segment lacking the potential for formation of the predicted hairpin structure involved in subgenomic expression. Antibodies made against purified nucleocapsids allowed serological comparison with other tospovirus isolates and revealed a relationship with tomato yellow ring virus, and to a lesser extent, to iris yellow spot virus. Serological tests detected the virus in various locations in northern and central Italy. The experimental host range was wide, although in nature the virus appeared restricted to two Polygonum species. [ABSTRACT FROM AUTHOR]

The article discusses the first report of a phytoplasma associated with abnormal proliferation of cladodes in cactus pear, Opuntia ficus-indica, in Italy. The cactus pears exhibited severe proliferation of cladodes with lack of flowers, fruits and spine production. Total DNA was extracted from both symptomatic and asymptomatic cactus pears. This was utilized as template for phytoplasma-specific 16S rDNA polymerase chain reaction amplification. The RFLP patterns acquired from analysis of rDNA amplicons were identical with the pattern obtained for reference strain faba bean phyllody phytoplasma.

This article is the first report of the potentially damaging virus Blueberry scorch virus (BlScV) outside North America. Highbush blueberry (Vaccinium corymbosum) has been planted in various areas of northern Italy for the past 30 years, in an effort actively to maintain cropped hillside and mountainside areas with acidic soil. The crop has also gained some economic importance for the fresh fruit market. During the summer of 2004, a number of plants from a blueberry crop field in southern Piedmont (Costigliole Saluzzo, Cuneo Province) showed symptoms generally associated with blueberry scorch disease.

Discusses the infection of Euphorbia eritrea and Asclepias curassavica by the tomato spotted wilt virus (TSWV) in Liguria, Italy. Detection of the disease by both enzyme-linked immunosorbent assay (ELISA) and immunochromatographic lateral flow assay; Transmission of the virus mechanically to common herbaceous test plant species.

Examines the pepino mosaic virus in tomato in Italy. Presence of potexvirus-like particles in tomato fruits and leaves; Dissemination route of the virus; Use of antiserum in detecting the virus.

We isolated a potyvirus from Tradescantia fluminensis that was causing leaf distortion and mild mosaic. We cloned and sequenced a 1500 bp cDNA obtained by RT-PCR corresponding to the 3' proximal region of the genome. We determined the host range and tested a series of potyviral antisera against our tradescantia virus isolate by immuno-enzymatic methods. Based on our results, we suggest that our viral isolate could be considered a new potyvirus species named Tradescantia mild mosaic potyvirus. Phylogenetic analysis confirmed that Tradescantia mild mosaic virus belongs to the genus Potyvirus within the family Potyviridae, but the virus could not be assigned to any of the potyvirus groupings recently defined.

Big-vein is a widespread and damaging disease of lettuce, transmitted through soil by the chytrid fungus Olpidium brassicae, and generally supposed to be caused by Lettuce big-vein virus (LBVV; genus Varicosavirus). This virus is reported to have rigid rod-shaped particles, a divided double-stranded RNA genome, and one capsid protein of 48 kD, but has not been isolated or rigorously shown to cause the disease. We provide evidence that a totally different virus, here named Mirafiori lettuce virus (MiLV), is also very frequently associated with lettuce showing big-vein symptoms. MiLV was mechanically transmissible from lettuce to Chenopodium quinoa and to several other herbaceous test plants. The virus was partially purified, and an antiserum prepared, which did not react with LBVV particles in decoration tests. As reported for LBVV, MiLV was labile, soil-transmitted and had a single capsid protein of 48 kD, but the particles morphologically resembled those of ophioviruses, and like these, MiLV had a genome of three RNA segments approximately 8.5, 1.9 and 1.7 kb in size. MiLV preparations reacted strongly in Western blots and in ISEM with antiserum to Tulip mild mottle mosaic virus, an ophiovirus from Japan also apparently Olpidium-transmitted. They reacted weakly but clearly in Western blots with antiserum to Ranunculus white mottle virus, another ophiovirus. When lettuce seedlings were mechanically inoculated with crude or partially purified extracts from MiLV-infected test plants, many became systemically infected with MiLV and some developed big-vein symptoms. Such plants did not react in ELISA using an LBVV antiserum or an antiserum to tobacco stunt virus, and varicosavirus-like particles were never seen in them in the EM after negative staining. We conclude that MiLV is a hitherto undescribed virus assignable to the genus Ophiovirus. The cause or causes of lettuce big-vein disease and the properties of LBVV may need to be re-evaluated in light of our results.