Phytophthora alni identified in the Czech Republic
A new disease of alder (Alnus spp.) causing tree mortality has been reported in Europe since the 1990s. A new species, Phytophthora alni (formerly EPPO Alert List), was described and detected in several European countries (see EPPO RS 2005/009) causing bleeding cankers and decline of alder trees. In the Czech Republic, an ‘alder Phytophthora’ was initially isolated from Alnus glutinosa in western Bohemia in 2001. A similar Phytophthora species was isolated from declining trees of A. glutinosa and A. incana from about 60 alder stands, mainly from the western part of the country. So far, extensive decline of alder has not been detected in the eastern part of the country (Moravia). Recent studies (morphology, DNA sequencing, pathogenicity tests) confirmed that the pathogen which is causing alder decline in the Czech Republic is Phytophthora alni.
Sources
New Disease Reports. BSPP website (last retrieved 2007-04).
Cerny K, Gregorova B, Strnadova V, Holub V, Tomsovsky M, Cervenka M (2007) Phytophthora alni causing decline of black and gray alders in the Czech Republic. http://www.bspp.org.uk/ndr/july2007/2007-36.asp