First Report of Honeysuckle yellow vein mosaic virus on tomato affected by yellow dwarf disease in Japan

Tomato plants exhibiting typical yellow dwarf symptoms (Fig. 1) were collected from three fields in Yanai-City, Yamaguchi-ken, Japan during 2000.

Total nucleic acid was extracted from infected tomato leaves and PCR performed using begomovirus-specific degenerate primers (Briddon ＆ Markham, 1994). A PCR-amplified product of expected size (approximately 2.7kbp) was obtained, cloned and sequenced. To sequence the remaining DNA region, additional degenerate primers Japan-V (5’-CCTGTGGGTGAATCCATGRTT-3’) and Japan-C (5’-TCCRAACATTCAGGGAGCTAA-3’) were designed and used for PCR. Wherever clones overlapped, their sequences were identical. We could not detect any DNA-B component in diseased plants using primers PCRc1 and PBLlv2040 (Rojas et al., 1993). The complete sequence of this begomovirus was determined as 2760 nucleotides and was deposited in GenBank (Accession number AB079765). Comparison of this sequence with those of other full length begomovirus DNAs in GenBank gave the highest similarity (92%) to that of honeysuckle yellow vein mosaic virus (HYVMV) (Accession No. AB020781). No DNA β was detected by Southern hybridization using HYVMD DNAβ as a probe, strongly suggesting that this virus is a monopartite begomovirus and a strain of HYVMV for which we propose the name Honeysuckle yellow vein mosaic virus-[Yamaguchi] (HYVMV-[Yam]). Tobacco leaf curl Japan virus is normally regarded as the cause of tomato yellow dwarf disease, causing heavy losses to tomato crops in Japan. This is the first report of HYVMV associated with tomato yellow dwarf disease in Japan.