© Benaki Phytopathological Institute
Abstracts - 16th Hellenic Phytopathological Congress
25
of Biology, Aristotle University of Thessaloniki, P.O Box:104, GR-541 24, Thessaloniki,
Greece.
4
Forest Service of Corfu, Alikes Potamou, GR-491 00 Corfu, Greece
The fungus
Cryphonectria parasitica
, the
causal agent of chestnut blight, was ob-
served in Greece for the first time in 1963
(Biris 1964) and particularly in Zagora, Mt.
Pelion. Examination of the mating type phe-
notype of
C. parasitica
isolates can reveal
the population structure and the presence,
or lack, of sexual reproduction. In 707 viru-
lent and hypovirulent isolates, fungal ge-
nomic DNA was extracted after growth on
PDA dishes covered with cellophane sheets.
Polymerase chain reaction was carried out
and the size of the PCR products was de-
termined to be 1,649 kb (MAT1-1) or 594 bp
(MAT1-2). The study of the sexual compati-
bility in our populations showed that the id-
iomorph MAT1-1 was present in most iso-
lates (92.6%). In contrast, only one isolate
(7.35%) was found to represent the MAT1-2
phenotype. This mating type distribution is
in agreement with the existing data for the
occurrence of only one mating type and
the lack of sexual reproduction. The results
of our study favour the application of bio-
logical control measures against chestnut
blight, a technique already in use for man-
agement of the disease in Greece.
Necrosis of young almond trees infected by
Botryosphaeria dothidea
A.I. R
UMBOU
1
and I.X. R
UMBOS
2
1
Center for Research and Technology, Thessaly (CERETETH), Volos, Greece.
2
Hellenic
Agricultural Organization “Demeter”, Plant Protection Institute of Volos, Greece
Several species of fruit trees have been re-
ported to be infected by fungi of the ge-
nus
Botryosphaeria
. Amongst these are ap-
ple, peach, pistachio, kiwifruit, olive and
walnut. Over the period May-June 2011
an unusual outbreak of the fungus was re-
corded at four new commercial almond (cv.
Ferragnes) plantations planted early in the
same year in the region of Thessaly, Central
Greece (in Tirnavos and New Anchialos). The
percentage of dead trees was between 40-
70% and the propagative material originat-
ed from two different nurseries in Thessa-
ly and North Greece. Infected trees showed
initially a yellowing discoloration of the
leaves and gradually died during the sum-
mer. All the infections were associated with
the pruning wound at the point of the union
of rootstock/scion. Transverse and longitu-
dinal sections through affected wood re-
vealed a brown discoloration of the wood
with a well defined line between the ne-
crotic and healthy tissues. From the root-
stock new vigorous shoots had often devel-
oped. The species
Botryosphaeria dothidea
(Moug.: Fr.) Ces. & De Not was isolated from
all trees examined. The fungus produced
hyaline, aseptate, fusiform conidia, 23-29
x 4.5-5 μm in size, belonging to
Neofusic-
occum mediterraneum
Crous, M.J. Wingf. &
A.J.L. Phillips (anamorph). The pathogenici-
ty of the obtained isolates was proved by in-
oculating young almond trees cv. Ferragnes
grown in the field. All isolates proved to be
pathogenic. Re-isolations made from discol-
ored wood yielded the same fungus. This is
the first report of infection of almond trees
in commercial plantations by the fungus
B.
dothidea
, worldwide.
Leaf spots induced in
Ilex aquifolium
by
Alternaria alternata
G.T. T
ZIROS
, C. P
ERLEROU
and S. D
IAMANDIS
Hellenic Agricultural Organization ‘’Demeter’’ (Ex NAGREF), Forest Research
Institute, GR-570 06 Vassilika, Thessaloniki, Greece
