SUMMARYA virus was transmitted from broad bean plants in Apulia (Southern Italy) with leaves showing yellow rings, line patterns or yellow vein banding and malformations and necrosis of pods. Symptoms in some, but not all, test plants were similar to those induced by tobraviruses. Purified virus preparations contained two classes of rod‐shaped particles containing c. 5% nucleic acid with sedimentation coefficients of 186S and 276S. After centrifugation to equilibrium in CsCl gradients, two components were resolved, with buoyant densities of 1·298 and 1·316 g/cm3. Unfractionated virus preparations contained two species of single‐stranded RNA with mol. wts of c. 1·06 × 106 and 2·48 × 106 and one species of coat protein with mol. wt of c. 21 300. The modal lengths of the two classes of particles, both in plant sap and in purified preparations, were 77 nm (S particles) and 202 nm (L particles). L particles accumulated in infected cells in paracrystalline aggregates, whereas S particles were randomly distributed in the cytoplasm of cells. The virus was serologically unrelated to two isolates of tobacco rattle virus and two isolates of pea early‐browning virus. The virus, named broad bean yellow band, is considered a distinct tobravirus.

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The biological and molecular characterization\ud is reported of a Watermelon mosaic virus isolate,\ud denoted WMV-Le, associated with a necrotic phenotype\ud of watermelon plants grown in the Provinces of\ud Lecce and Taranto (Apulia, southern Italy). The fully\ud sequencedWMV-Le genome consists of 10,045 nucleotides\ud and is 99.1% similar to that of WMV-C05-270, a\ud French isolate from melon of the WMV molecular\ud group 3. Using recombination detection programRDP3,\ud putative recombination breakpoints were identified\ud close to nucleotide positions 42 to 1892, covering the\ud 5′UTR/P1/HC-Pro region. The event represents the\ud insertion of a sequence fragment of an isolate similar to\ud WMV-FBR04-37 in the background of an isolate similar\ud to WMV-FMF00-LL1. The field symptomatology was\ud reproduced in watermelon plants grown in an experimental\ud greenhouse but the virus induced severe symptoms\ud also in Cucumis sativus, C. melo, Cucurbita\ud maxima and C. pepo

An isometric virus was isolated from cucumber plants growing in a plastic house in Crete and showing stunting and bright yellow mosaic of the leaves. Based on host range, properties in crude sap, behaviour during purification, electron microscopy and serology, the virus was identified as an isolate of artichoke yellow ringspot nepovirus. Ecological data corroborate transmission of the virus via the soil.

An isometric virus c. 30 nm in diameter with a single RNA species (mol.wt 1.45 X isolated from cucumber plants from the island of Crete (Greece) is described under the name of cucumber fruit streak virus (CFSV). The most evident symptom on naturally infected plants consisted of longitudinal chlorotic streak of the fruits. In glasshouse, the virus was soil-transmi'tted to C. sativuSy and, mechanically, to a wide range of herbaceous hosts, most of which were infected only locally.Purified virus preparations sedimented as a single component with sedimentation coefficient of 132S. At equilibrium these preparations were homogeneous in CsCl gradient.^ but formed two bands in Cs^SO^ gradients. Virus particles were stabilized by forces involving divalent cations, pH-dependent bonds and salt links between protein and RNA. Although some of the properties of CFSV are similar to those of other small spherical viruses with single RNA species there are differences which do not allow for the assignment of 'the virus to any of established taxonomie group of plant viruses. Zusammenfassung Einige Eigenschaften des Cucumber fruit streak virusDas aus Gurkenpflanzen auf der Insel Kreta (Griechenland) isolierte isometrische Virus (ungefahr 39 nm Durchmesser, mit einer einzigen RNA-Art [Molekulargewicht 1,45 X lQe]) wird unter der Bezeichnung ,,Cucumber fruit streak virus" (CFSV) besdirieben. Das offcnsichtlichste Symptom bei natiirlich infizierren Pflanzen bestand aus langslaufenden chlorotischen Streifen an den Friichten. Im Gewachshaus wurde das Virus auf C. sativus durch die Erde und auf ein weites Spektrum anderer krautartiger Wirtspflanzen mechanisch ubertragen. Die letzjtgenannten Pflanzen waren meist nur ortlidi angegriffen. U.S. Copyright Clearance Center Code Statement: 0031-948l/83/0602-0149$02.50/0 GM.I.ITKLLI, VOVLAS and AVGELIS Virusprapiiratc scdimonticrtcn als einzigc Komponenite mit einem Sedimentations-kocfU/iontcn von 132S. Ausgcwogcn waren diese Praparate in CsCl-Gradientcn homogen, jcdoch biidcten sie in Cs.,SO^-Gradienten zwei Banden. Die Korngrofie der Viren wurde durdi Kriiftc, an denen divalen^te Kationen, pH-bedingtc Bindungen und Salzverbindungen zwischen dciii Protein und RNA beteiligt waren, stabilisiert. Obwohl einige Eigenschaften JL'S Cl'SV L\cn anJcri'ii kleinsphiirischen Viren mit einer einzigen RNA-Art ahneln, sind die Untcrsdiicdc doch zu grof^, um dieses Virus einer taxonomlsch bestehcnden Gruppe der Pflanzenviren zuzuordnen.