Identification and analysis of genomic sequence of broad bean wilt virus 2 isolated from celeriac
[Objective]This study aimed to obtain the complete genome sequence of the broad bean wilt virus 2(BBWV 2)iso-late from Apium graveolens var.rapaceum in Inner Mongolia and analyze its sequence identity,phylogenetics,and recombina-tion in comparison with other BBWV 2 isolates.[Methods]Suspected virus-infected leaf samples of A.graveolens var.rapace-um were collected.Next-generation sequencing(NGS)technology was employed to identify the virus species present in the samples.RT-PCR and Rapid Amplification of cDNA Ends(RACE)were utilized to verify the virus species.The complete ge-nome sequence of the cloned BBWV 2 Inner Mongolia isolate 20IM-ApGr was analyzed using software such as VectorNTI,MEGA11,SDTV1.2,and RDP4.[Results]The complete sequences of the two RNAs of the BBWV 2 Inner Mongolia iso-late,20IM-ApGr,were successfully cloned.Sequence identity analysis showed that the amino acid sequence identity of 20IM-ApGr with other isolates ranged from 85.2%to 99.5%in the Pro-RdRp region and 82.8%to 92.7%in the CPs region.Phy-logenetic trees based on the Pro-RdRp and CPs regions of the BBWV 2 genome grouped known isolates into two clades.The isolates obtained in this study were classified into Clade II and showed the closest relationship with Chinese pepper isolates Hu-nan and XJ14-3.[Conclusion]The causative agent of yellowing and shrinking in A.graveolens var.rapaceum leaves was identi-fied as BBWV 2.This study successfully obtained the complete genome sequence of the BBWV 2 Inner Mongolia isolate for the first time,elucidating its evolutionary relationship with known BBWV 2 isolates.These findings provide a theoretical foun-dation for the classification and genetic evolution study of BBWV 2 strains.