Molecular Identification and Genetic Diversity Analysis of Papaya Leaf Curl China Virus Infecting Ageratum conyzoides.

Papaya leaf curl China virus (PaLCuCNV) is a damaging plant pathogen causing substantial losses to crop. The complete genomes of three PaLCuCNV isolates from Ageratum conyzoides were obtained and combined with the 68 reference isolates in GenBank for comprehensive genetic diversity analyses using specialized computational tools. Sequence alignment revealed nucleotide sequence similarity ranging from 85.3% to 99.9% among 71 PaLCuCNV isolates. Employing phylogenetic analysis, 71 PaLCuCNV sequences were clustered into five groups, with no significant correlation observed between genetic differentiation and either host species or geographical origin. Additionally, 13 recombination events across all PaLCuCNV isolates were identified. Genetic diversity analysis indicated the ongoing expansion and evolution of PaLCuCNV populations, supported by a neutral model. Moreover, significant genetic differentiation was observed among distinct viral populations, primarily attributed to genetic drift. Overall, our findings provide valuable insights into the detection, genetic variation, and evolutionary dynamics of PaLCuCNV.