Page 20 - Volume 1, Issue 1, January 2008

K. Elena et al. 18
presence for the first time in the country
and in particular the Israeli virus species
(TYLCV-Is) (Avgelis et al., 2001). More than
30 ha of tomato greenhouses were affect-
ed and the disease incidence ranged from
15 to 60%. All affected greenhouses were
infested by dense populations of the vi-
rus vector B. tabaci, also observed outside
the greenhouses on several weeds. Since
then the virus has become endemic in the
above mentioned regions and has been
reported in others as well (Preveza, Kardit-
sa). In 2005 a new epidemic occurred in
Crete, Southern Peloponnese and Rhodes
island. Molecular analysis revealed recent-
ly the presence of a second species name-
ly TYLCSV in Peloponnese and Crete (Pa-
pagiannis et al., 2007a). Both species are
commonly found in mixed infections and
are spread by the vector and the exchange
of commercial products from one country
to another. Lately, the virus was found on
bean (Phaseolus vulgaris L.) plants (1-5%)
co-cultivated with infected tomatoes and
showing typical symptoms caused by Be-
gomoviruses. Since bean is often used as
an intercrop between tomato crops, in-
fected plants may serve as a potential re-
servoir for virus survival and spread (Papa-
giannis et al., 2007b).
3.2.3. Transmitted by hoppers
Cucumber toad-skin virus 
(CTSV, genus Nucleorhabdovirus)
In 1993-1994, virus-like symptoms were
observed in glasshouse growing cucumbers
in Thessaloniki and Preveza at a very low inci-
dence (1-2%). Affected plants showed severe
stunting, leaf crinkling, vein clearing and
fruit deformation. Biological indexing and
electron microscopy suggested infection by
CTSV (Katis et al., 1995) and recent research
based on serology and RT-PCR revealed that
CTSV is a variant of Eggplant mottled dwarf
virus (EMDV, genus Nucleorhabdovirus) (Ka-
tis, personal communication), transmitted
persistently by a leafhopper.
Eggplant mottled dwarf virus 
(EMDV, genus Nucleorhabdovirus)
EMDV was reported to occur in tomato
(syn. Tomato vein yellowing virus) (Kyriako-
poulou, 1995) and tobacco crops (Chatzi-
vassiliou et al., 2001; 2004). Tobacco pro-
ducing areas in Greece were surveyed for
virus presence, from 1997 to 2000, and
EMDV was detected in several areas (La-
mia, Kilkis, Drama, Karditsa and Komoti-
ni) but always its incidence was very low
(<0.01%). The virus is transmitted by the
leafhopper Agallia vorobjevi (Dlabola) in a
persistent manner.
Maize rough dwarf virus 
(MRDV, genus Fijivirus)
In 2002, maize (Zea mays L.) crops
grown in Northern Greece (Macedonia),
showed severe dwarfing, reduced cob
size and in some cases leaf reddening.
The dwarfing disease was epidemic and
in some regions (Imathia and Serres) crop
losses over 70% were estimated. Symp-
toms were different from those caused by
Maize dwarf mosaic virus, which is endemic
in maize crops in Macedonia. In 2003, only
a few cases were recorded. Serological
and molecular analysis identified MRDV
as the causal organism (Dovas et al., 2004).
The virus is transmitted by planthoppers
of the family Delphacidae in a persistent
manner.
3.3. Mechanically transmitted viruses
Cymbidiummosaic virus  (CymMV, ge-
nus Potexvirus), Odontoglossum ring-
spot virus (ORSV, genus Tobamovirus)
In 1998, orchid plants belonging to the
genera Cymbidium and Phalenopsis and
showing chlorotic and necrotic lesions
and stripes were found in a greenhouse
near Patras (Achaia). Mechanically trans-
mitted CymMV and ORSV were diagnosed
by serology (ELISA), electron microscopy,
artificial inoculation of indicator plants
and polymerase chain reaction (PCR) (Do-
vas et al., 2001d).