Selection of a nucleopolyhedrovirus isolate from Helicoverpa armigera as the basis for a biological insecticide
2014
Arrizubieta, Maite | Williams, Trevor | Caballero, Primitivo | Simón, Oihane
BACKGROUND: The cotton bollworm, Helicoverpa armigera, is an insect that causes damage in a wide range of crops in Spain. Seven isolates of H. armigera single nucleopolyhedrovirus (HearSNPV) from the Iberian Peninsula were subjected to molecular and biological characterization and compared with a Chinese genotype (HearSNPV‐G4). RESULTS: The estimated sizes of the Iberian genomes varied between 116.2 and 132.4 kb, compared to 131.4 kb of the HearSNPV‐G4 reference genome. Phylogenetic analysis based on the lef‐8, lef‐9 and polh genes revealed that the Iberian strains were more closely related to one another than to other HearSNPV isolates. Occlusion body (OB) concentration‐mortality responses (LC₅₀ values) did not differ significantly among Iberian isolates when tested against a Helicoverpa armigera colony from Oxford (UK). Despite being the fastest killing isolate, HearSNPV‐SP1 was as productive as isolates with lower virulence, with an average yield of 3.1 × 10⁹ OBs larva⁻¹. OBs of HearSNPV‐SP1 and HearSNPV‐G4 were similarly pathogenic against a recently established colony from southern Spain, although HearSNPV‐SP1 was faster killing than HearSNPV‐G4 against a range of instars. CONCLUSION: The insecticidal properties of HearSNPV‐SP1 mean that this strain is likely to prove useful as the basis for a biological insecticide for control of Helicoverpa armigera in Spain. © 2013 Society of Chemical Industry
显示更多 [+] 显示较少 [-]