Molecular characterization of Endothia gyrosa isolates from Eucalyptus in South Africa and Australia

Endothia gyrosa is a canker pathogen best known as the causal agent of pin oak blight in North America, and causes cankers on other woody hosts such a s Castanea srp. and Liquidambar spp. In South Africa, Australia and Tasmani a, a fungus identified as E. gyrosa has been recorded on Eucalyptus spp. So me morphological differences exist between the North American fungus and th e isolates from Eucalyptus. Phylogenetic relationships between E. gyrosa fr om North America and E. gyrosa from South Africa and Australia, as well as that of the related fungi Cryphonectria parasitica and C. cubensis, were st udied using PCR-based restriction fragment length polymorphism (RFLP) and s equences of the internal transcribed spacer (ITS) region of the rRNA operon . Endothia gyrosa isolates from South Africa produced the same RFLP banding patterns as those from Australia, which differed markedly from North Ameri can isolates of E. gyrosa. In a phylogram based on the DNA sequences, the A ustralian and South African isolates of E. gyrosa resided in a single, well reserved clade, distinct from North American isolates. Isolates of C. para sitica grouped in the same clade as the South African and Australian isolat es of E. gyrosa, but C. cubensis was distantly related to them. The molecul ar data suggest that the E. gyrosa isolates from South Africa and Australia represent a distinct taxon, and probably belong to the genus Cryphonectria .