© Benaki Phytopathological Institute
Abstracts - 16th Hellenic Phytopathological Congress
63
free experimental fields in Kozani, resulted
in a significant reduction in the
S. kali
weed
population, and its almost complete eradi-
cation over the following 2-3 years. The dis-
tribution of the inoculum was performed in
a natural manner, and commenced with the
first rains at the end of August. Naturally in-
fected
C. arvense
leaves, bearing the telio-
sori of
P. punctiformis
were collected from
a field in Kozani. Inoculation of young
C. ar-
vense
rosettes, in a disease-free experimen-
tal field in Kozani, has shown that successful
inoculations take place only during autumn.
The percentage of successful inoculations
was low, and multiple inoculum applica-
tions were necessary during this period.
However, the establishment of the patho-
gen in the field was successful. The progress
of the disease over the following years is be-
ing studied.
Screening of Greek Trichoderma isolates as potential biocontrol agents of
soilborne fungal pathogens
G.A. B
ARDAS
, P. A
GGELOPOULOU
, H. E
FSTRATIOU
, G. T
ZINOGLOU
, G. M
OUTOULI
, A. T
SANAKTSIDOU
G. P
ALATOS
and S. S
TEFANOU
Alexander Technological Educational Institution of Thessaloniki, GR-574 00 Sindos,
Thessaloniki, Greece
The general inadequacy of chemical fun-
gicides for the control of
Verticillium dahli-
ae
,
Rhizoctonia solani
,
Pythium ultimum
and
Sclerotinia sclerotiorum
on several plant
hosts has led to a survey for biocontrol so-
lutions. Thirty two
Trichoderma
spp. iso-
lates
were isolated and identified, on the
basis of their morphological characteris-
tics and by molecular analysis of the inter-
nal transcribed spacer 1 and 2 regions (ITS1
and ITS2). These isolates
were evaluated for
their antagonistic activity against the soil
borne plant pathogens
in vitro
. Different iso-
lates showed varying degrees of biocontrol
activity. Specifically, regarding mycoparasit-
ism tested using a dual culture technique,
seven
Trichoderma
sp. isolates, identified
as
Trichoderma asperellum
and
Trichoderma
harzianum
, showed enhanced mycoparasit-
ic activity on pathogen colonies. Regarding
antibiotic activity, two
Trichoderma viride
isolates exhibited increased pathogen sup-
pression due to the production of volatile
and non volatile metabolites.
The chitino-
lytic (chitinase and NAGase) activity of the
Trichoderma
species tested varied, as to the
carbon source (colloidal chitin,
R. solani
cell
wall material) targeted and the location of
these enzymes (mycelium, liquid). In detail,
Trichoderma harzianum
B2 and
Trichoderma
viride
B4 isolates were characterized as be-
ing highly productive of endochitinase, ex-
ochitinase and β-Ν-acetylhexosaminidase.
In conclusion, the promising results of this
research could form the basis of an extend-
ed study, in order to evaluate the efficacy of
these biocontrol agents
in planta
.
Evaluation of the biocontrol efficacy of
Paenibacilus alvei
strain K165
against
Fusarium oxysporum
f.sp.
melonis
S.E. T
JAMOS
, A. C
HARALAMPOUS
and E.J. P
APLOMATAS
Laboratory of Plant Pathology, Agricultural University of Athens, 75 Iera Odos Str.,
GR-118 55 Athens, Greece
The plant pathogen
Fusarium oxysporum
constitutes one of the most significant
threats to farmers’ revenue worldwide, hav-
ing more than a hundred
formae specialis
with differing host specificities. In the pres-
ent research, the efficacy of the biocontrol
agent
Paenibacilus alvei
K165 to control
Fu-
sarium oxysporum
f.sp.
melonis
was studied.
