A novel virus of the Partitiviridae family was detected in asymptomatic carnation (Dianthus caryophyllus, L.) using high-throughput sequencing (HTS). This novel virus was provisionally named Dianthus caryophyllus cryptic virus 1 (DcCV1) with the tentative species name Deltapartitivirus dianthicrypticum. Its genome comprises three double-stranded RNA (dsRNA) of 1657, 1496, and 1435 nucleotides. The largest dsRNA encodes P1 protein (477 amino acids) which was identified as the viral RNA-dependent RNA polymerase (RDRP) with six conserved motifs specific to RDRPs of double-stranded RNA viruses. The second dsRNA encodes protein P2 (347 amino acid), which is the coat protein (CP), and the third dsRNA encodes P3 protein (347 amino acid), of unknown function. The 5’ untranslated region of the three dsRNAs has a highly conserved 9-nucleotide (nt) sequence (5’ GATAATGAT 3’) similar to some deltapartitiviruses in their 5′-untranslated regions (UTR). Based on the demarcation criteria of species in the Partitiviridae family, Deltapartitivirus dianthicrypticum is proposed as a new species. RT-PCR using CP gene-specific primers (1044 bp) followed by sequencing confirmed the presence of DcCV1 in carnation plant. This is the first report of DcCV1 in carnation, the fourth-cryptic virus of this ornamental.

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