Research has been conducted in the Czech Republic since 2006, in which a team of which an expert from the Faculty of Forestry and Wood Sciences was a member examined the spread of two dangerous, invasive, probably non-native, mutually related pathogens Phytophthora multivora and P. plurivora. They were first isolated in 1927 on orange trees in Taiwan. The aim of the study was to determine their distribution, pathogenicity, extent of penetration into natural ecosystems and potential danger for tree stands in the Czech Republic.
During the study, more than 160 isolates of both species were obtained from more than 20 host trees that showed the presence of this fungus. Samples were taken from both ornamental and forest trees, from a number of systems, from completely artificial (horticultural centres or greenhouse cultures) to natural vegetation. It turned out that both species occur in all monitored types of environment and that these pathogens differ in frequency of occurrence (87 % of isolates belonged to the species P. plurivora) and their range. The species P. plurivora occurs more or less widely throughout the Czech Republic at various altitudes, while P. multivora was identified only in the lower parts of Central Bohemia and South Moravia.
It follows from the above that the first species (P. plurivora) invaded the territory much earlier than the second species, while the beginning of the P. multivora invasion is recent and the pathogen is just beginning to spread. P. multivora first occupies the lowest, most man-loaded and altered areas.
Within Europe, the spread of this pathogen in natural ecosystems is documented for the first time (in Europe it has so far only been detected in ornamental nurseries). During the research, the partial substrate specificity of the more widespread species P. plurivora was also identified – strains obtained from forest trees (oak, beech, etc.) were more pathogenic to the tested tree species than strains from ornamental trees (e.g. rhododendrons). Differences in damage to the tested tree species were also found. The most sensitive was the beech, among the less sensitive woods were the maple, the oak and the ash. Surveys of oak stands in South Moravia show that P. plurivora and P. multivora may pose a major risk to European forests in the future.
Ing. Ludmila Havrdová
Ing. Ludmila Havrdová, (* 1975), studied under the CULS at the Department of Agri-environmental Chemistry and Plant Nutrition. She is currently working as a researcher at VÚKOZ, v. v. i., Průhonice and is completing his doctoral studies at the Department of Game Management and Wildlife Biology, Faculty of Forestry and Wood Sciences, CULS, Prague.
Prepared by: Tomáš Krištof