di studio del CNR sui virus e le virosi delle colture mediterranee, via Amendola 165/A, 70126Bari (Italy) **Istituto Agronomico Mediterraneo, via Cegli 9, 70010 Valenzano, Bari (Italy) The biological and physicochemical characterization of two almond isolates of prune dwarf ilarvirus (PDV), carried out in comparison with six other PDV isolates from other Prunus species, showed that the various isolates could not be differentiated from one another, if it were not for the field syndromes they were associated with. To ascertain the occurrence of serological PDV variants in nature, monoclonal antibody technology was applied. One PDV isolate (PDV-IAM1 1) from Prunus mahuleb in Puglia (Southern Italy) was used as antigen. After fusion of murine (balb/C) splenocytes with NSO/l myeloma cells, eight different hybridoma lines secreting PDV-IAM11-specific antibodies were selected, cloned, and denoted PD-3, PD-6, PD-7, PD-8, PD-9, PD-10, PD-11 and PD-12. Their use in the serological characterization of the eight PDV isolates under study, by DAS-ELISA, gave rise to three different serotype groups, one of which (PDV-B) comprised only the two almond isolates. Examination of 120 additional samples collected from field-grown PVD-infected Prunus trees (40 of which were almonds) confirmed the existence in nature of a wide range of serological PDV variants, which yielded 36 different types of reactants (tentative serogroups). The PDV-B serotype was detected in 38% of the almond trees tested, but only in three of the other 86 PDVinfected Prunus plants. These results demonstrate that serological differentiation among PDV isolates is possible, and that PDV-B, one of the tentative serotypes identified, seems preferentially associated with almond.
Production d'anticorps monoclonaux du prune dwarf ilarvirus et leur utilisation pour la caracterisation serologique de ses isolats sur amandierLa caracthisation biologique et physico-chimique de deux isolats de l'amandier du prune dwarf ilarvirus (PDV), rCalisCe en comparaison avec six isolats d'autres esp&ces de Prunus, a montrk que les diffkrents isolats ne peuvent pas &re distinguis les uns des autres, sauf pour les sympdmes qu'ils provoquent en plein champ. La technologie des anticorps monoclonaux a Ct C utiliste pour vCrifier l'existence dans la nature de variants sCrologiques du PDV. Un isolat (PDV-IAM1 1) de Puglia (sud de 1'Italie) provenant de Prunus mahaleb a CtC utilisi c o m e antigbne. Aprks fusion de splknocytes munns (balb/C) avec des cellules de myClome NSO/l, huit lignCes hybrides sCcrCtant des anticorps spCcifiques ? i PDV-JAM1 1 ont Ct C sklectionnbes, clonies, et nomkes PD-3, PD-6, PD-7, PD-8, PD-9, PD-10, PD-11 et PD-12. Leur utilisation pour la caractkrisation sCrologique, par DASI-ELISA, des huit isolats de PDV Ctudiks a permis de dCgager trois groupes de skrotypes, dont un (PDV-B) comprend uniquement les deux isolats de l'amandier. L'Ctude de 120 Cchantillons supplementaires pr6levCs sur des Prunus cultivts en plein champ et infect& par le PDV (dont 40 amandiers), a c...