Characterization of genotypic and phenotypic variation in plaque-purified strains of HzSNPV Elkar isolate.

Twenty plaque-purified strains of Heliothis zea S-type nuclear polyhedrosis virus (HzSNPV) were characterized based upon restriction endonuclease digests of viral DNAs, structural protein profiles, and larval melanization response. Each of the 20 strains had a unique genotype. Genomic heterogeneity between strains was localized to 4 regions of the HzSNPV genome. Differences in protein profiles of occluded virus were noted for each strain relative to the wild-type isolate. The strains were separated into 3 groups based upon differences in relative virulence and rate of larval melanization upon death. There was no correlation between differences in pathology and specific alterations in either genotype or structural proteins. The genotype of strain HzS-15 was extensively characterized. Physical maps were constructed for the HzS-15 strain and all of the plaque-purified strains.