Genome sequencing, Analysis and Characterization of Baculovirus Infecting the Caterpillar, Spilosoma Obliqua Walker (Arctiidae) (Insecta: Lepidoptera) from India
The Bihar hairy caterpillar, Spilosoma obliqua is an economically important polyphagous insect and to reduce its pest density, baculoviruses are considered as the ideal eco-friendly pathogens under the pest management program. A nucleopolyhedrovirus infecting Spilosoma obliqua (SpobNPV) has been found to be a promising pathogen in the present study. Our report describes the pathogenicity, structural details and genome sequence characterization of SpobNPV-Manipur isolate. The pathogenicity of the virus was studied in terms of median lethal concentration (LC50) and survival time (ST50) and the LC50 of SpobNPV on third instar larvae was 2.7 x 105 POBs/ml and the median survival time (ST50) was 144 hours. The occlusion bodies (OBs) of the virus were purified and the viral genome was sequenced, annotated and compared with other baculoviruses. The sequenced genome of SpobNPV-Manipur isolate was 136,306 bp in length with GC content of 44.9% and it comprises a total of 144 ORFs. The gene content analysis suggested the presence of 13 SpobNPV genes associated with replication, 12 genes associated with transcription and 31 structure related genes. The pathogenicity, structural information and genome resources of SpobNPV-Manipur isolate virus can be utilized further to understand its molecular and genetic mechanisms and improve its efficacy in pest management through recombinant DNA technology.