September 29, 2005
From: British Society for
Plant Pathology, New Disease Reports, Vol. 12 [edited] <http://www.bspp.org.uk/ndr/jan2006/2005-70.asp>
Potato deforming mosaic disease is caused by an isolate of
Tomato yellow vein streak virus
S.G. Ribeiro,
Embrapa Recursos Geneticos e Biotecnologia, Pq. Estacao
Biologica, Brasilia, DF, Brazil; A.K. Inoue-Nagata, Embrapa
Hortalicas, C. Postal: 0218, 70359-970, Brasilia, DF, Brazil; J.
Daniels, Embrapa Clima Temperado, Rodovia BR 392, km 78,
Pelotas, RS, Brazil; and A.C. de Avila (Inoue-Nagata) Accepted
for publication 8 Sep 2005.
The disease known as potato deforming mosaic was first reported
in the 1980's in Southern Brazil (Daniels & Castro, 1985).
Symptoms of mosaic with leaf distortion were seen in infected
potato plants and a virus was
suggested as the causal pathogen. In this study, we have
characterised the causal agent of this disease by transmission
experiments and molecular analysis of the viral genome.
The original virus isolate was collected from a potato plant in
1983 in the State of Rio Grande do Sul and maintained through
vegetative propagation in the greenhouse. The virus was easily
transmitted from potato by the whitefly _Bemisia tabaci_ biotype
B causing mottling, chlorotic spots and leaf distortion on
tomato, vein-banding and mosaic on _Nicotiana benthamiana_ and
vein-clearing on _Nicandra physaloides_. These properties
are consistent with the disease agent being a geminivirus.
PCR amplification using primers CP2
(5'cccctgcagaacttccaagtctggacg3') and PAL1v1978 (Rojas et al.,
1993) produced a DNA A derived fragment of 1.8 Kb encoding the
entire coat protein gene, common region and part of the AC1
gene. Sequence comparison showed highest identity (97.3 percent)
to Tomato yellow vein streak virus (ToYVSV-U79998), a virus
previously described in tomatoes in Brazil (Faria et al., 1997).
The presence of a B component was confirmed by PCR with primers
B1200F 5'CCCCTGCAGTAYTAYTGYTGGATGTC3') and B1900R
(5'cccctgcagrtgyaacatwgatctcc3'); with amplification of a
fragment of approximately 800nt comprising the 3' end of the BV1
gene, the small intergenic region and the 5' half of the BC1
gene.
Our results indicate that the potato deforming mosaic and tomato
yellow vein streak diseases are caused by the same geminivirus,
belonging to the genus _Begomovirus_. Potato deforming mosaic
disease was described more
than 20 years ago but was of little economical relevance
(Daniels & Castro, 1985). Since then this virus, now named
Tomato yellow vein streak virus (ToYVSV), has re-emerged and is
currently the major begomovirus affecting tomatoes and potatoes
in the state of Sao Paulo (Souza-Dias et al., 2003).
This is the 1st record of natural infection of ToYVSV in potato.
Acknowledgement
We wish to thank Dr Marcel Prins for his
comments.
References
Daniels, J, Castro LAS, 1985. Ocorrencia do
virus do mosaico deformante da batata no Rio Grande do Sul.
Fitopatologia Brasileira 10, 306.
Faria JC, Souza-Dias JAC, Slack S, Maxwell DP, 1997. A new
geminivirus associated with tomato in the State of Sao Paulo,
Brazil. Plant Disease 81, 423.
Rojas MR, Gilbertson RL, Russell DR, Maxwell DP, 1993. Use of
degenerate primers in the polymerase chain reaction to detect
whitefly-transmitted geminiviruses. Plant Disease 77, 340-347.
Souza-Dias JAC, Sawasaki HE, Santini A, 2003. Plantio sucessivo
de batata e tomate na regiao de Sumare, SP favorece a presenca
do Tomato yellow vein streak geminivirus (ToYVSV) e da mosca
branca vetora. Fitopatologia
Brasileira 28, 372.
--
ProMED-mail
<promed@promedmail.org>
[It is interesting that it took over 20 years to recognize that
ToYVSV and Potato yellow deforming virus were one and the same
virus. In potato, the apical leaves showed yellow or green
mottle which developed into leaf
distortion with yellow blotches (apparently no natural infection
have been found on potato). About 20 percent of young tomato
plants showed virus symptoms. Tomato is an important crop in the
EPPO region, and both indoor
and outdoor and the virus vector is present in many parts of the
EPPO region. The disease appears so far, limited in Brazil but
data is lacking about its extent and severity. It is not known
whether potato can be naturally infected
Links:
<http://gemini.biosci.arizona.edu/viruses/toyvsv/>
<http://www.scielo.br/scielo.php?pid=S0100-41582003000200007&script=sci_abstract&tlng=en>
- Mod.DH]
[see also in the
archive:
2000
Tomato yellow vein streak begomovirus 20000502.0666]