© Benaki Phytopathological Institute
Hellenic Plant Protection Journal - Special Issue
60
the chemical groups of substances exhibit-
ing substantial nematicidal activity. The ac-
tivity of the extracts was verified against
various growth stages of the parasite
in vivo
;
while enzyme (AchE) inhibition activities
were determined
in vitro
. Fumigant prop-
erties were also evident, an effect that is of
paramount importance in nematode con-
trol as it enhances nematicidal activity in ad-
jacent, untreated soil layers.
Insights into the development of natural ne-
maticidals for use in ecofriendly agriculture
are presented.
Effect of several plant extracts and chitosan on
Chrysanthenmum stunt
viroid
(CSVd) infections of chrysanthemum plants
I.N. B
OUBOURAKAS
and M. H
OSOKAWA
Laboratory of Vegetable and Ornamental Horticulture, Department of Agronomy
and Horticultural Sciences, Graduate School of Agriculture, Kyoto University
Chrysanthemum stunt viroid
(CSVd) consti-
tutes a serious problem for chrysanthemum
cultivation worldwide and especially in Ja-
pan. Infection is extremely difficult to avoid,
as chrysanthemum is propagated vegeta-
tively, CSVd is readily transmissible, and the
disease has a long latent period. The pres-
ent study investigated whether extracts of
Mirabillis japala
,
Pelargonium
sp.,
Phytolac-
ca americana
,
Capsicum chinense
,
Oleae eu-
ropaea
,
Brassica
sp.,
Bougainvillea
sp.,
Hout-
tuynia
sp.,
Dendranthema grandiflorum
Kitam cv. Sei-no-issei,
Allium cepa
,
Allium sa-
tivum
plants and Chitosan-100 could reduce
CSVd titre in highly infected plants
in vitro,
and/or prevent CSVd titre increase in new-
ly-infected plants
ex vitro
. Ten to 15 plants
were used per treatment and the viroid load
was estimated weekly using one step Real
Time RT-PCR.
C. chinense
, Houttuynia, Bou-
gainvillea and chitosan were the treatments
that stood out, resulting in statistically sig-
nificant (t-test) reductions in CSVd titres,
ranging from 35 to 50%. The application of
chitosan to
ex vitro
plants prevented CSVd
titre increase (50% to 70%) compared to
control and seemed to have a positive effect
on plant height. Experiments using CSVd
RNA treated with plant extracts and chito-
san were also performed in order to quan-
tify viroid degradation. Results showed that
pepper and chitosan extracts were as effec-
tive as sodium hypochlorite treatment. In
conclusion, chitosan and extracts of
Capsi-
cum
sp.,
Houttuynia
sp. and
Bougainvillea
sp.
were found to be promising for use in chry-
santhemum stunt viroid disease manage-
ment.
Impact of
Cucumber mosaic virus
(CMV) infection and benzothiadiazole
(BTH) application on the quantitative and qualitative traits of marketable
tomato fruits
M. K
ALOGIROU
1,2
, C. V
ARVERI
1
, N. V
ASSILAKOS
1
AND
L.A. T
ERRY
2
1
Laboratory of Virology, Benaki Phytopathological Institute, 8 St. Delta Str., GR-145
61 Kifissia, Athens. Greece.
2
Plant Science Laboratory,
Cranfield University, College
Road, Bedfordshire, MK43 0AL, United Kingdom
This study evaluated the effect of
Cucum-
ber mosaic virus
(CMV) infection and benzo-
thiadiazole (BTH) application (BION 50 WG,
50 mg/L), individually or in combination, on
several quantitative and qualitative traits of
tomato fruits produced from greenhouse-
grown F1 Delos plants during two successive
seasons. CMV caused the most severe stunt-
ing of tomato plants compared to the oth-
er treatments (CMV+BTH, BTH, healthy con-
trol plants) and resulted in significant loss
of marketable fruits, although the total fruit
