IDENTIFICATION OF GREMMENIELLA-ABIETINA RACES WITH RANDOM AMPLIFIED POLYMORPHIC DNA MARKERS

Seven random amplified polymorphic DNA (RAPD) markers amplified from f our oligonucleotides (10-mers) by the polymerase chain reaction were u sed to distinguish between the North American and European races of Gr emmeniella abietina, the causal agent of Scleroderris canker of conife rs. Forty-three isolates of the pathogen from 11 different host specie s originating from 11 countries, states, and provinces were tested; ra ce designation was consistent with results from immunogenic and solubl e-protein assays. By using RAPD markers, it was possible to identify G . abietina races by DNA amplifications directly from fruiting bodies, thus eliminating the need to culture the fungus, as is necessary with immunogenic and soluble-protein assays. Two isolates which had been pr eviously classified as intermediate were clearly identified as belongi ng to either one of the two races by using RAPD markers. No interracia l hybrids were detected in our survey. Patterns of amplification produ cts from the European race in North America were identical to patterns of European isolates, further substantiating that this is an introduc ed race to the North American continent.