|XII Congreso de
la Sociedad Española de Fitopatología (SEF), 2004
Estudio de las poblaciones de Cryphonectria parasitica en
Castaños de Galicia
Aguín, O.; Mansilla,
J.P.; Pintos, C.
Estación Fitopatolóxica do Areeiro,
Excma. Diputación Provincial de Pontevedra, Subida a la Robleda s/n,
36153 Pontevedra, España.
ABSTRACT: Chestnut is a
forestry species of important commercial value, both for its highly appreciated
wood and for fruit production. One of the most severe diseases affecting this
species and that is causing great loss in our region is known as chestnut
blight and is caused by the fungus Cryphonectria parasitica. At present,
this pathogen is widely disseminated around all chestnut groves in Galicia,
however, so far there is not information on its real distribution. The aim of
the present work, result of an agreement between our research centre and the
Consellería de Medio Ambiente de la Xunta de Galicia (Environmental
Division of the Galician government), is to know the current distribution of
Cryphonectria parasitica in Galician chestnut groves, to detect
hypovirulent strains naturally occurring in the region, and to determine the
structure and diversity of their vegetative compatibility types. A survey was
performed in the four Galician provinces, comprising 130 municipalities and
1060 sites, and collecting 466 symptomatic samples in total. Under laboratory
conditions, and subjected to a superficial disinfection, plant material was
sown in PDAmb culture media. Isolate virulence was determined by means of the
analysis of their morphological features and by dsRNA extraction. Vegetative
compatibility study of C. parasitica isolates was performed in PDAg
media. Compatibility types were paired against European testers (EU1 to EU64).
Results proved that most bark samples were affected by C. parasitica
virulent strains, only detecting two hypovirulent strains in Lugo province.
Although 8 compatibility types were found, 70% of these isolates belonged to a
single group. Only the compatibility type know as E (8% of the isolates) was
compatible with the European tester, EU1.