Seleção genetica do virus de poliedrose nuclear de Autographa Californica (Baculoviridae) em diatraca saccharalis (Fabr., 1974) (Lepidoptera pyralidae)

AUTOR(ES)
DATA DE PUBLICAÇÃO

1989

RESUMO

The genetic variant E2 from the Autographa californica Nuclear Polyedrosis Virus (AcNPV) was serially passed for five generations in its alternate host Oiatraea saccharalis the sugarcane borer. From these passages four isolates were obtained besides the original inoculum (IV-I, IV-2, IV-3, IV-4 and E2). These isolates were compared to each other considering larval mortality, mode and timing of action, morphology of the polyhedra, polyhedral production and protein profile. As a result of this analysis the following results and conclusions were reached: a) The AcNPV-E2 was able to infect and produce infective polyhedra in its alternate host Diatraea saccharalis. b) A drastic and progressive increase in the virulence of the AcNPV isolates, indicated by thousand fold reduction of the LD50 values, was observed for D. saccharalis larvae. c) The increasing presence of abnormal larger cubic shaped polyhedra opposed to the regular polyhedra in the forth generation of the virus isolate (IV-4). d) A two fold increase in the number of polyhedral volume was observed when comparing the original (E2) and the selected inoculum (IV-4) e) A 16 fold reduction in the number of polyhedra produced per gram of infected larvae was observed when comparing the original inoculum (E2) and the forth generation (i. e. virus produced by inoculum IV-3). The inoculation of IV-4 resulted in an almost total absence of polyhedra in the infected larvae. f) The AcNPV isolates presented differences in the protein profile in the SDS polyacrilamide gel electrophoresis (SDS-PAGE). g) Based on the protein profile and biological activity the five isolates can be separated in the three groups, E2/IV-1, IV-2 e IV-3/ IV-4, indicating a growing virulence followed by an progressive alteration of peptides. The IV-2 isolate in both perspectives represents an intermediate group. h) The protein differences were not observed with the treatment of SDS and 2-mercaptoethanol in the purification procedure.

ASSUNTO(S)

virus - seleção lepidoptera

ACESSO AO ARTIGO

Documentos Relacionados