Genomic detection and molecular characterization of two distinct isolates of cycas necrotic stunt virus from Paeonia suffruticosa and Daphne odora.

Complete genome sequences of two cycas necrotic stunt virus (CNSV) isolates from Paeonia suffruticosa and Daphne odora were determined. Phylogenetic trees and pairwise comparisons using complete RNA1- and RNA2-encoded polyproteins showed that the two CNSV isolates are divergent (83.19%-89.42% in polyprotein 1 and 73.61%-85.78% in polyprotein 2). A comparative analysis based on taxonomic criteria for the species demarcation of nepoviruses confirmed that they are not new species but distinct variants. This is the first report of the complete genome sequences of CNSV detected in P. suffruticosa and D. odora, and the first report of CNSV infecting P. suffruticosa.