J.Th.J. Verhoeven*, M. Botermans, C.C.C. Jansen and J.W. Roenhorst
Plant Protection Service, P.O. Box 9102, 6700 HC Wageningen, The Netherlands
Received: 03 Nov 2010; Published: 22 Mar 2011
In the summer of 2009 in a greenhouse in the south of Ontario, Canada, up to 3% of the plants of the pepper cvs. Score and Lamborgini (Capsicum annuum) showed mild growth reduction and abnormally small fruits (Fig. 1). Symptoms were observed spreading along the rows. These observations suggested the presence of Pepper chat fruit viroid (PCFVd), a viroid recently described infecting capsicum pepper in the Netherlands (Verhoeven et al., 2009). For diagnosis, two small-sized pepper fruits of cultivar Lamborgini were sent by the grower to the Plant Protection Service of the Netherlands. The fruits were tested in a single sample by reverse transcription polymerase chain reaction (RT-PCR) with primer pairs Pospi1-RE/FW (Verhoeven et al., 2004) and AP-FW1/RE2 (Verhoeven et al., 2009), which produced amplicons of 193 and 335 bp for PCFVd, respectively. The complete viroid genome of 348 nt was derived from overlapping sequence fragments, after directly sequencing RT-PCR products (GenBank Accession No. HQ731652). BLAST analysis of the obtained sequence showed a 100% of sequence identity to that of the PCFVd isolate from the Netherlands (FJ409044) (Verhoeven et al., 2009). In addition, the Canadian isolate was mechanically inoculated to young plants, four each for capsicum pepper cv. Yolo Wonder and tomato (Solanum lycopersicum) cv. Moneymaker. The tomato plants developed symptoms after four weeks of inoculation, including chlorosis and stunting, whereas no symptoms were observed on the post-inoculated pepper plants. After six weeks, the presence of the viroid in the post-inoculated plants was confirmed for both plant species by RT-PCR with primers Pospi1-RE/FW in bulked samples of four plants.
Although PCFVd may be transmitted through capsicum pepper seed, a direct relationship between the outbreaks in Canada and the Netherlands seems unlikely as different cultivars from different seed companies were involved (Verhoeven et al., 2009). Symptomless infected ornamental host plants may have been the source of infection of pepper plants in the Ontario greenhouse, as reported for the Potato spindle tuber viroid in tomato. Thus ornamentals may pose a phytosanitary risk for vegetable crops (Navarro et al., 2009; Verhoeven et al., 2010). The grower was encouraged to notify the Canadian phytosanitary authorities of these findings.
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Verhoeven JThJ, Jansen CCC, Willemen TM, Kox LFF, Owens RA, Roenhorst JW, 2004. Natural infections of tomato by Citrus exocortis viroid, Columnea latent viroid, Potato spindle tuber viroid and Tomato chlorotic dwarf viroid. European Journal of Plant Pathology , 823-831. [http://dx.doi.org/10.1007/s10658-004-2493-5]
Verhoeven JThJ, Jansen CCC, Roenhorst JW, Flores R, De la Peña M, 2009. Pepper chat fruit viroid: biological and molecular properties of a proposed new species of the genus Pospiviroid. Virus Research 144, 209-214. [http://dx.doi.org/10.1016/j.virusres.2009.05.002]
Verhoeven JThJ, Jansen CCC, Botermans M, Roenhorst JW, 2010. Epidemiological evidence that vegetatively propagated, solanaceous plant species act as sources of Potato spindle tuber viroid inoculum for tomato.Plant Pathology 59, 3-12. [http://dx.doi.org/10.1111/j.1365-3059.2009.02173.x]
Verhoeven JTJ, Botermans M, Jansen CCC, Roenhorst JW, 2011. First report of Pepper chat fruit viroid in capsicum pepper in Canada. New Disease Reports 23, 15. [http://dx.doi.org/10.5197/j.2044-0588.2011.023.015]
©2011 The Authors