First report of a typical calico-associated isolate of Peach latent mosaic viroid from calico disease-affected peach trees in Korea.
Peach latent mosaic viroid (PLMVd), a member of the genus Pelamoviroid in the family Avsunviroidae, may be symptomless or causes yellow, chlorotic mosaics and delays in foliation, flowering, and ripening, with fruit deformation and discoloration. In June 2016, naturally infected peach trees (Prunus persica) cv. Akatsuki showing severe chlorosis of leaves, stems, and fruits were observed in Gyeongsan, South Korea, symptoms similar to the PLMVd-induced peach calico (PC) disease. Leaf tissue samples were collected individually from four symptomatic plants in the same commercial field. Results of PCR assay and phylogenetic analysis of the nucleotide sequences revealed a typical calico-associated isolate of PLMVd. This is thought to be the first report of a PLMVd isolate with the typical calico-associated hairpin insert inducing PC of peach trees in Korea; the potential emergence of PC-inducing PLMVd variants from latent isolates suggests that certification schemes for peach in Korea should include freedom from PLMVd.