Crayfish plague epizootics in Germany - classification of two German isolates of the crayfish plague fungus Aphanomyces astaci by random amplification of polymorphic DNA

Following 2 outbreaks of crayfish plague in southern Germany, the causative agent, the oomycete fungus Aphanomyces astaci, was isolated from the disea sed Astacus astacus. The identity of the 2 strains was confirmed using esta blished techniques, such as physiology, spore production and the fact that the isolated strains were highly virulent for A. astacus in infection exper iments. The relationship between these German strains and other A. astaci s trains was investigated using randomly amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR). The German strains were found to be closely rel ated to a strain that had been isolated from Pacifastacus leniusculus from Lake Tahoe, USA.