Three novel viruses detected from Japanese persimmon 'Reigyoku' associated with graft-transmissible stunt.

Three novel viruses were detected from Japanese persimmon 'Reigyoku' (Diospyros kaki), which grows poorly when top-grafted onto some interstocks. The genomic characterization and the phylogenetic analysis of these viruses indicated that they are likely new members of the genera Ampelovirus, Polerovirus, and Waikavirus, tentatively named Persimmon ampelovirus (PAmpV), Persimmon polerovirus (PPolV), and Persimmon waikavirus (PWaiV). The alignment of two PAmpV variants with Plum bark necrosis stem pitting–associated virus isolates had 72.5%–79.0% amino acid sequence identities with RNA-dependent RNA polymerase, 71.6%–79.2% with a heat shock protein 70 homolog, and 66.2%–69.8% with coat protein, respectively. Two PPolV variants showed the highest amino acid sequence identities (46.6%) with the P1–P2 fusion protein of Brassica yellows virus. PWaiV had the highest amino acid sequence identity (41.9%) with the conserved domain between proteinase and polymerase of Rice tungro spherical virus. Reverse-transcription and polymerase chain reaction detected Persimmon virus A, Apple crinkle fruit viroid, and Citrus viroid VI from the mother clone with good growth, and PAmpV, PPolV, and Persimmon latent viroid (PLVd) additionally from 20 trees with poor growth. PAmpV, PPolV, and PLVd were detected from four, 10, and 10 of 14 trees with good growth, respectively, and the grafting of budwood harboring these three pathogens caused significant stunt in mother clones. [ABSTRACT FROM AUTHOR]