In September 2008, Narcissus plants originating from commercial nurseries in Taranaki (TK) in New Zealand's North Island and Canterbury (CB) in the South Island were received showing leaf mottling, flower distortion, and color break. The CB plant also showed stunting. Filamentous virus particles (700 to 900 nm long) were seen in crude sap of both plants with a transmission electron microscope. Total RNA was isolated from the leaves of both plants with an RNeasy Plant Mini Kit (Qiagen, Chatsworth, CA), and cDNA was synthesized by Superscript III (Invitrogen, Carlsbad, CA). cDNA was used in PCR to test for viruses in the following genera: Allexivirus, Carlavirus, Cucumovirus, Nepovirus A and B, Potyvirus, Potexvirus, Tospovirus, and Tobravirus. Both plants tested positive for potyvirus using generic potyvirus primers (3). Amplicons from both plants were directly sequenced. The forward and reverse sequence from the CB plant matched sequences in the GenBank database for Narcissus late season yellows virus (NLSYV) and Narcissus degeneration virus (NDV), respectively. The potyvirus amplicon from the CB plant was cloned and sequenced. Sequence from independent clones was obtained for NLYSV only (No. FJ546721), and this sequence showed 97% nucleotide identity to NLYSV No. EU887015. The CB plant was tested with a second set of generic potyvirus primers using forward (PV1SP6) (2) and reverse primers (U335) (1). BLASTN analysis of the sequence obtained from independent clones (No. FJ543718) matched sequence for NDV only (97% nucleotide identity to No. AM182028). BLASTN analysis of the potyvirus obtained for the TK plant (No. FJ546720) showed 97% nucleotide identity to NLSYV (No. EU887015). The TK plant also tested positive for a carlavirus using commercial primers (Agdia, Elkhart, IN) and unpublished generic carlavirus primers (A. Blowers, personal communication). Amplicons from both PCRs were cloned and sequenced. BLASTN analysis of both sequences (Nos. FJ546719 and GQ205442) showed 94% nucleotide identity to Narcissus symptomless virus (NSV) No. AM182569. Both plants were also tested for NLSYV, Narcissus virus Q, Narcissus latent virus, and Narcissus yellow stripe virus by indirect ELISA (Neogen, Lansing, MI). Results confirmed the presence of NLSYV in both plants but the plants were negative for the other viruses. NLSYV has been detected previously from Narcissus pseudonarcissus L. (daffodil) (D. Hunter, personal communication); however, to our knowledge, this is the first official report of NDV, NLSYV, and NSV in New Zealand. Since both plants tested negative for several other viruses by PCR and ELISA, this would suggest that the symptoms observed may have been caused by NSV, NLSYV, NDV, or as a result of a mixed infection. However, symptoms were not confirmed using Koch's postulate. NSV has been reported in the literature as symptomless. NLYSV has been reported to be a possible cause of leaf chlorosis and striping and NDV has been associated with chlorotic leaf striping in N. tazetta plants (4). Since Narcissus is an important flower crop for domestic production in New Zealand, the reduction in flower quality observed when these viruses are present may be of economic significance in commercial nurseries.
References: (1) S. A. Langeveld et al. J. Gen. Virol. 72:1531, 1991. (2) A. M. Mackenzie et al. Arch Virol. 143:903, 1998. (3) V. Marie-Jeanne et al. J. Phytopathol. 148:141, 2000. (4) W. P. Mowat et al. Ann. Appl. Biol. 113:531, 1988.
