CHARACTERIZATION OF 2 TOSPOVIRUSES IN ITALY - TOMATO SPOTTED WILT ANDIMPATIENS NECROTIC SPOT

Tospovirus serogroups I and III have recently been designated as speci es, tomato spotted wilt virus (TSWV) and impatiens necrotic spot virus (INSV), while the species status of serogroup II isolates remains und efined. Fifteen Tospovirus isolates from ornamental and vegetable crop s in Liguria, Italy, were found to belong either to TSWV (seven isolat es) or to INSV (eight isolates) on the basis of test-plant reactions, serological techniques using DAS ELISA kits raised against the nucleop roteins of the type members of the two species, and cytopathology. Non e of them could be assigned to serogroup II using DAS ELISA kits raise d against nucleoproteins of this serogroup. Italian isolates represent ative of the two species reacted in indirect ELISA using a polyclonal antiserum against the entire particle of a TSWV isolate, but with high er intensity for our TSWV isolates than for the INSV isolates. Western blots and dot immunobinding assays confirmed that the nucleoproteins of the two species are unrelated whereas the glycoproteins are related . The cytopathology was similar for two isolates representative of TSW V and INSV, except that the type of filaments encountered was differen t, and appeared to be characteristic of the species.