Laboratory toxicity bioassay and genome sequence analysis of a new field isolate of Spodoptera frugiperda multiple nucleopolyhedrovirus
The fall armyworm,Spodoptera frugiperda,is a major agricultural pest invading China.Spodoptera frugiperda multiple nucleopolyhedrovirus(SfMNPV)is a specific pathogen targeting this pest.In this study,we isolated a new strain of multiple embedded SfMNPV from Nanchang,Jiangxi province,named SfMNPV_JX.Toxicity assay demonstrated that it exhibited high bioactivity against local fall armyworm larvae,with LC50 of 1.634×105 PIB/mL.The genome of SfMNPV_JX was sequenced and assembled,revealing 140 open reading frames(ORFs)and a length of 134 241 bp.Phylogenic analysis classified SfMPV_JX as a Group Ⅱ alpha-baculovirus closely related to Spodoptera frugiperda multiple nucleopolyhedrovirus isolate Colombian(SfMNPV_Colombian),sharing 97.85%sequence identity.This study provides foundational data for developing environmentally friendly biopesticides against the invading pest S.frugiperda.