First report of Phytophthora quercina in Turkey
In the Asian part of Turkey, surveys were carried out in forests from 1999 to 2001. Mature trees of several oak species showed symptoms of decline, including thinning of the crown, yellowing and wilting of leaves, branch dieback and growth of epicormic shoots on branches and trunk. Observations over time confirmed a slow progress of tree mortality. Soil samples including fine roots with necrotic lesions were collected, and leaf baits were also used, in order to study the presence of Phytophthora species. 10 species of Phytophthora were isolated and P. quercina (EPPO Alert List) was the most frequently isolated species (isolated from 29 sites, i.e. 57 %). This is the first report of P. quercina in Turkey. Isolates from Turkey showed some slight morphological differences with the haplotype, as well as a lower optimal temperature and higher growth rate when compared with European strains. P. quercina was also isolated on new hosts: Quercus hartwissiana, Q. frainetto and Q. vulcanica. Observations suggest that P. quercina is widespread in Turkey and occurs within the natural range of oak, which raises the question of its role in the oak decline syndrome.
Sources
Balci, Y.; Halmschlager, E. (2002) First confirmation of Phytophthora quercina in Asia.
Plant Disease, 86(4), p 442.