The endophytic mycobiota of healthy twigs and the assemblage of
species associated with twig lesions of Eucalyptus globulus and
E.
grandis planted at the same site in the central west region of Uruguay
was examined. Twig segments from E. grandis and E. globulus
were plated on 2% malt agar. The diversity of endophytes isolated was low,
as was the number of host-specific species. E. globulus
endophytes of healthy xylem were different from the colonizers of cracked
lesions and healthy bark. Conversely, in E. grandis
characterized by black spots, the main difference in species composition
was between xylem and bark. Cytospora chrysosperma was
isolated from healthy bark and symptomatic twigs of E. globulus,
suggesting that symptomatic tissues, such as cracks produced under
drought were favourable to saprotrophic expansion.