First Report of Wisteria vein mosaic virus on Wisteria sinensis in New Zealand.

Wisteria vein mosaic virus (WVMV) is a member of the Potyvirus genus. The virus has been reported in Wisteria spp. in Australia, China, the United States, and a number of European countries (2). In 2006, several W. sinensis plants with mottling and mosaic symptoms were observed in a commercial plant nursery in Whenuapai, north of Auckland, New Zealand. These plants had been propagated from a nursery in the New Plymouth area of New Zealand. Sap from the symptomatic Wisteria plants was examined with an electron microscope and elongated and flexuous potyvirus-like particles approximately 750 nm long were observed. RNA was extracted from the symptomatic plants with a Qiagen RNeasy Plant Mini Kit (Doncaster, Australia). The RNA was initially tested using general potyvirus primers, PV1/SP6 (4) and U335 (3), with the cycling conditions of 94°C for 5 min followed by 40 cycles of 94°C for 45 s, 50°C for 45 s, 72°C for 90 s, and a final extension of 72°C for 7 min. The polymerase chain reaction (PCR) product (695 bp) was directly sequenced (GenBank Accession No. EU580146) and a BLAST search in GenBank showed 98% nucleotide identity with WVMV (GenBank Accession no. AF484549). The RNA was then tested using WVMV-specific primers, WVMVF1 and WVMVR1, and the published cycling conditions (2). PCR amplicons of 701 bp were obtained. PCR products were directly sequenced (GenBank Accession No. EU308592), and a BLAST search in GenBank showed 98% nucleotide identity with published sequences of WVMV (GenBank Accession Nos. AF484549 and AY656816). In addition, RNA was extracted from the original isolate of WVMV that was reported in the Netherlands (1; supplied by R. van der Vlugt, Plant Research International) and the RNA was amplified using the WVMV-specific primer pair. The sequence obtained from PCR amplicons of the type isolate (GenBank Accession No. EU308593) showed a 98% nucleotide identity with the New Zealand WVMV isolate and with published sequences of WVMV (as shown above). From the symptomatology, particle morphology, and nucleotide sequences, it is concluded that WVMV is present in New Zealand. The distribution of the virus in New Zealand is not known, but the affected plants at the New Plymouth nursery may have been imported into New Zealand as many as 30 years ago. Although WVMV infection can reduce the quality of commercial plants, the disease is not economically significant in New Zealand. References: (1) L. Bos. Neth. J. Plant Pathol. 76:8, 1970. (2) G. R. G. Clover et al. Plant Pathol. 52:92, 2003. (3) S. A. Langeveld et al. J. Gen Virol. 72:1531, 1991. (4) A. M. Mackenzie et al. Arch Virol. 143:903, 1998.