Genetic variation in Australian isolates of the grapevine pathogen Eutypa lata

Eutypa lata is an ascomycete fungus that causes eutypa dieback of grapevines, a disease which threatens vine productivity and longevity throughout the world. We assessed genetic variation among 35 isolates received as E. lata from Australia, Europe, California and South Africa using restriction fragment length polymorphism analysis. A subset of 10 isolates previously analysed for secondary metabolite production was also analysed using randomly amplified polymorphic DNA markers. Molecular analyses showed a high level of genetic diversity, with each isolate having a unique haplotype. Phylogenetic analysis did not allow separation of isolates based on geographic location or host species from which isolateswere obtained. Therewas no apparent correlation betweenDNAprofile and secondary metabolite production by E. lata. The results of this study showed a degree of genetic diversity similar to that reported for European and North American populations of E. lata, and are consistent with the hypothesis that the sole means of dispersal of the pathogen is by ascospores.