A PCR-based technique for the identification of Aphanomyces invadans.

Results and Discussion The Aph3-Aph4 primers reacted with DNA extracted from mycelium of a range of A. invadans isolates from different countries and host fish species. A 98bp product was produced from each reaction. A few non-specific bands were also produced. The saprophytic Aphanomyces species and other Oomycete fungi tested also produced a range of band patterns, but none succeeded in producing the 98bp band. The PCR test is therefore a useful means of differentiating A. invadans cultures from other fungal species.