Biochemical characterization of three nucleopolyhedrovirus isolates of Spodoptera exigua and Mamestra brassicae

Three nucleopolyhedroviruses (NPVs), of different geographical origins, wer e biochemically characterized and compared. Two that were isolated from Spo doptera exigua (Se-UZB and Se-SP3) in Uzbekistan and Spain were SeMNPV type , and the third which was isolated from Mamestra brassicae (Mb-PL) in Polan d was MbMNPV type. The Spanish isolate Se-SP3 showed restriction endonuclea se (REN) profiles that were closely related to two previously described Spa nish strains Se-SP1 and Se-SP2, but had some unique and characteristic REN fragments. On the other hand, comparison between the Uzbekian (Se-UZB) and the Spanish (Se-SP1, Se-SP2, and Se-SP3) isolates from S. exigua showed unr elated REN profiles. However, the PstI and BglII profiles of Se-UZB and MB- PL were identical, and very similar to the REN profiles of the MbMNPV strai n, which constitutes the active component of Mamestrin((R)) (NPP, Nagueres, France), a commercial bioinsecticides. It is therefore very likely that th e Se-UZB samples were cross-infected by the Polish strain (Mb-PL). This wor k presents two new strains of SeNPV and MbMNPV, called Se-SP3 and Mb-PL, re spectively, which were surveyed in two distant areas.