S. Veerakone

First report of Narcissus degeneration virus, Narcissus late season yellows virus, and Narcissus symptomless virus on Narcissus in New Zealand.

In September 2008, Narcissus plants originating from commercial nurseries in Taranaki (TK) in New Zealands 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 The TK plant also tested positive for a carlavirus using commercial primers (Agdia, Elkhart, IN) and unpublished generic carlavirus primers (A. Blowers, personal communication).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 Kochs 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.

A review of the plant virus, viroid, liberibacter and phytoplasma records for New Zealand

A complete review of the records of plant virus, viroid, liberibacter and phytoplasma in New Zealand has found evidence for 220 viruses, seven viroids, two liberibacters and two phytoplasmas. Of these, 80 viruses, one viroid and two species of liberibacter have been reported as new to New Zealand since the last review in 2006. Ten viruses and two viroids, which were previously placed in the unconfirmed category, have now been confirmed. Based on insufficient evidence, 25 virus, three viroid, three mollicute and 36 disease records are considered unconfirmed.

The complete nucleotide sequence and genome organisation of a novel member of the family Betaflexiviridae from Actinidia chinensis

We report the complete genome sequence of a novel virus, tentatively named “actinidia seed-borne latent virus” (ASbLV), isolated from Actinidia chinensis in Auckland, New Zealand. The complete genome of ASbLV is 8,192 nucleotides long, excluding the 3ʹ poly(A) tail, contains four open reading frames, and is most closely related to Caucasus prunus virus (56% nucleotide sequence identity), a member of the genus Prunevirus. Based on the demarcation criteria of the family Betaflexiviridae, ASbLV is a new member of the genus Prunevirus.

First report of a carlavirus in Fuchsia spp. in New Zealand.

The genus Fuchsia has 110 known species and numerous hybrids. These ornamental plants with brightly colored flowers originate from Central and South America, New Zealand, and Tahiti, but a wider variety are now grown all over the world. Few viruses have been reported in Fuchsia spp.: a carlavirus, Fuchsia latent virus (FLV) (1-3), a cucumovirus, Cucumber mosaic virus (CMV) (3), and two tospoviruses, Impatiens necrotic spot virus (INSV) and Tomato spotted wilt virus (TSWV) (4). In August 2009, five plants, each representing a different cultivar of Fuchsia hybrid, from home gardens in the Auckland and Southland regions of New Zealand, displayed variable symptoms including mild chlorosis, mild mottle, or purple spots on leaves. Plants tested negative for CMV, INSV, and TSWV using commercial ImmunoStrips (Agdia Inc., Elkhart, IN); however, flexuous particles of ~650 to 700 nm were found by electron microscopy in all samples. Local lesions were also observed on Chenopodium quinoa plants 4 weeks after sap inoculation. Total RNA was extracted from all plants with a RNeasy Plant Mini Kit (Qiagen Inc., Doncaster, Australia) and tested by reverse transcription (RT)-PCR using two generic sets of primers (R. van der Vlugt, personal communication) designed to amplify fragments of ~730 and 550 bp of the replicase and coat protein genes of carlaviruses, respectively. Amplicons of the expected size were obtained for all samples, cloned, and at least three clones per sample were sequenced. No differences within clones from the same samples were observed (GenBank Accession Nos. HQ197672 to HQ197681). A BLASTn search of the viral replicase fragment showed the highest nucleotide identity (76%) to Potato rough dwarf virus (PRDV) (EU020009), whereas the coat protein fragment had maximum nucleotide identity (70 to 72%) to PRDV (EU020009 and DQ640311) and Potato virus P (DQ516055). Sequences obtained were also pairwise aligned using the MegAlign program (DNASTAR, Inc., Madison, WI) and results showed that the isolates had 83 to 97% identity to each other within each genome region. Further sequences (HQ197925 and HQ197926) were obtained from a Fuchsia plant originating from Belgium, a BLASTn analysis showed high nucleotide identity (84 to 99%) to the New Zealand isolates. The low genetic identity to other Carlavirus members suggests that these isolates belong to a different species from those previously sequenced. On the basis of electron microscopy and herbaceous indexing, the isolates had similar characteristics to a carlavirus reported from Fuchsia in Italy (1) and FLV reported in Canada (2). The Italian carlavirus isolate was obtained and tested with the same primers by RT-PCR. Pairwise analysis of the Italian sequences (HQ197927 and HQ197928) with the New Zealand and Belgian sequences showed between 84 and 95% similarity within each genome region. These results suggest that the carlavirus infecting these plants is the same virus, possibly FLV. To our knowledge, this is the first report of this carlavirus infecting Fuchsia spp. in New Zealand, but the virus has probably been present for some time in this country and is likely to be distributed worldwide. References: (1) G. Dellavalle et al. Acta Hortic. 432:332, 1996. (2) L. J. John et al. Acta Hortic. 110:195, 1980. (3) P. Roggero et al. Plant Pathol. 49:802, 2000. (4) R. Wick and B. Dicklow. Diseases in Fuchsia. Common Names of Plant Diseases. Online publication. The American Phytopathological Society, St. Paul, MN, 1999.