Passiflora latent virus (PLV) naturally infects cultivated and wild Passiflora species in Australia, Germany, Israel and the United States (1--3). In March 2004, chlorotic lesions were observed on leaves of three vines of Passiflora tarminiana on one site in Auckland, New Zealand. Chenopodium amaranticolor and C. quinoa inoculated with sap from symptomatic leaves developed chlorotic local spots, followed by systemic leaf chlorosis and necrosis. Local symptoms appeared more quickly on C. quinoa (12 days) than on C. amaranticolor (20 days). No symptoms were observed on inoculated plants of Nicotiana benthamiana, N. clevelandii, N. occidentalis, N. tabacum, or Phaseolus vulgaris. Electron microscopy of crude sap preparations from infected C. quinoa, C. amaranticolor, N. occidentalis, and P. tarminiana showed flexuous, filamentous virus particles approximately 650 nm long. Plants of P. tarminiana and the three inoculated indicator species containing virus particles tested positive by PLV polyclonal antiserum in double-antibody sandwich (DAS)-ELISA (DSMZ, Braunschweig, Germany) and immunosorbent electron microscopy (Stephan Winter, DSMZ, personal communication). Nucleic acid was extracted from leaves of plants of each of the four viruliferous species with an RNeasy Plant Mini Kit (Qiagen, Doncaster, Australia) and then used in reverse transcription (RT)-PCR tests with novel forward (5′-CGAGACACACGCAAACGAA-3′) and reverse (5′-CAGCAAAGCAAAGACACGA-3′) primers specific to a 523-bp fragment of the PLV polyprotein. PCR products of the expected size were obtained, and an amplicon from P. tarminiana was directly sequenced (GenBank Accession No. EU257510). A BLAST search in GenBank showed 94% nucleotide sequence identity with a PLV isolate from Israel (GenBank Accession No. DQ455582). To our knowledge, this is the first finding of PLV in P. tarminiana and the first report of the virus in New Zealand. Chenopodium spp. have been reported previously as experimental hosts (2,3), and this study revealed that N. occidentalis also can be infected latently with PLV. P. tarminiana is a weed in New Zealand and subject to active control measures to manage the species. Economically important species such as P. edulis and P. ligularis are potentially susceptible to the virus. These species are not grown commercially in the surrounding area but are common in domestic Auckland gardens. Infected vines were removed from the site and destroyed, and symptomatic vines have not been observed at other sites.
References: (1) R. D. Pares et al. Plant Dis. 81:348, 1997. (2) S. Spiegel et al. Arch. Virol. 152:181, 2007. (3) A. A. Stihll et al. Plant Dis. 76:843, 1992.
