Occurrence and Genomic Characterization of Japanese Iris Necrotic Ring Virus Isolated from Narcissus spp. in Korea

Metatranscriptome analysis and reverse transcription polymerase chain reaction (RT-PCR) were performed on 75 Narcissus to investigate viral disease, leading to the detection of Japanese iris necrotic ring virus (JINRV, Betacarmovirus iridis). RT-PCR detected JINRV in 22 of 75 samples, all collected from Shinan, with a regional infection rate of 55.0% (22/40). The complete genome sequence of JINRV isolate SA36 was 4,060 nucleotides long and contained five open reading frames. Sequence analysis revealed that Narcissus-derived JINRV isolates shared 98.0-100% coat protein amino acid identity among themselves, and 71.9-91.5% with previously reported Iris-derived isolates. Sap inoculations showed that JINRV was mechanically transmitted to Cucurbita pepo. JINRV was exclusively detected in plants co-infected with other viruses, reflecting the complex mixed infection status prevalent in Narcissus. This study is expected to contribute to the quarantine of Narcissus bulbs and to the production of high-quality Narcissus in Korea.