New Disease Reports
New Disease Reports (2009) 20, 4.
Next > < Prev

Columnea latent viroid (CLVd): first report in tomato in France

S. Steyer 1*, T. Olivier 1, A. Skelton 2, T. Nixon 2 and E. Hobden 2

*steyer@cra.wallonie.be

Show affiliations

Accepted: 22 Sep 2009

In summer 2007, leaves and fruits from tomato (Solanum lycopersicum) cv. Santa with symptoms of virus-like disease were received for diagnosis from glasshouse crops in Western France. Samples tested negative by ELISA for common tomato viral diseases: Cucumber mosaic virus (CMV), Tobacco mosaic virus (TMV), Tomato spotted wilt virus (TSWV), viruses in the Potyvirus group, Pepino mosaic virus (PepMV) and Tomato yellow leaf curl virus (TYLCV). Affected plants displayed viroid-like symptoms including severe leaf yellowing or reddening, in addition to distortion and stunting (Fig. 1).

To determine whether the symptoms were caused by a viroid infection, samples were first tested for Potato spindle tuber viroid (PSTVd) and the pospiviroid group by reverse transcription-polymerase chain reaction (RT-PCR). The ‘semi-specific’ PSTVd-h/c primers (Shamloul et al., 1997), the universal Vir 1/2 (Mumford et al., 2000) and the Vid-FW/RE (Verhoeven et al., 2004) primer sets were used. All tests gave negative results, even with the last primer sets, initially designed to detect CLVd isolates. Since Columnea latent viroid (CLVd) is the only viroid not detected by the universal Vir 1/2 primers, a specific test based on primers pCLV4/pCLVR4 was conducted (Spieker, 1996) and a product of the predicted size (~370 bp) was obtained. BLAST analysis of the sequenced amplicons (GenBank Accession Nos. FM995506 and FM995507) revealed that the highest identity (99.1% similarity) was with a CLVd isolate recently identified in tomato in England (Accession No. FJ394070, Nixon et al., 2009). Infection by CLVd was confirmed by two methods: mechanical inoculation on to a tomato plant cv. Marmande followed by RT-PCR using the specific pCLV4/pCLVR4 primers; or by a Scorpion real-time RT-PCR assay, followed by RT-PCR and sequencing using specific CLVd primers (unpublished, Accession Nos. FJ715462 and FJ715463). To our knowledge, this is the first report of CLVd in tomato in France where the authorities have been duly informed. The origin of the infection is still unknown.

Figure1+
Figure 1: CLVd symptoms showing (a) yellowing of the leaves, (b) leaf reddening
Figure 1: CLVd symptoms showing (a) yellowing of the leaves, (b) leaf reddening
Figure2+
Figure 2: Phylogenetic tree using MEGA 4.0 obtained from ClustalW alignments of the complete genome of CLVd isolates with the sequence of the French isolates (Accession No. FM995506 and FM995507). Potato spindle tuber viroid (Accession No. M16826) was used as sequence outgroup. The number at nodes indicate bootstrap confidence values (1000 replicates) and the scale represents the number of base substitutions per site.
Figure 2: Phylogenetic tree using MEGA 4.0 obtained from ClustalW alignments of the complete genome of CLVd isolates with the sequence of the French isolates (Accession No. FM995506 and FM995507). Potato spindle tuber viroid (Accession No. M16826) was used as sequence outgroup. The number at nodes indicate bootstrap confidence values (1000 replicates) and the scale represents the number of base substitutions per site.

Acknowledgements

The authors would like to thank E. Demonty and M. Collard for their excellent technical assistance.

References

  1. Mumford RA, Walsh K, Boonham N, 2000. A comparison of molecular methods for the routine detection of viroids. EPPO Bulletin 30, 431-436.
  2. Nixon T, Glover R, Mathews-Berry S, Daly M, Hobden E, Lambourne C, Harju V, Skelton A, 2009. Columnea latent viroid (CLVd) in tomato: the first report in the United Kingdom. New Disease Reports [http://www.bspp.org.uk/publications/new-disease-reports/volumes.php] Volume 19.
  3. Shamloul AM, Hadidi A, Zhu SF, Singh RP, Sagredo B, 1997. Sensitive detection of potato spindle tuber viroid using RT-PCR and identification of a viroid variant naturally infecting pepino plants. Canadian Journal of Plant Pathology 19, 89-96.
  4. Spieker RL, 1996. A viroid from Brunfelsia undulata closely related to the Columnea latent viroid. Archives of Virology 141, 1823-1832.
  5. Verhoeven JTJ, 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 110, 823-831.
This report was formally published in Plant Pathology

©2009 The Authors