Sphaeropsis sapinea and Botryosphaeria dothidea endophytic in Pinus spp and Eucalyptus spp in South Africa

Sphaeropsis sapinea (Fr.: Pr.) Dyke & B. Sutton and the anamorph of Botrycsphaeria dothidea (Moug.) Ces, et De Not. are morphologically and ecologically similar fungi that cause serious canker and die-back diseases of Pinus and Eucalyptus spp. respectively in South Africa. In this article, the presence of both these fungi as symptomless endophytes in healthy pine and eucalypt tissue was demonstrated. Sphaeropsis sapinea was present in 50% of young, green P. patula Schl. et Cham., and 90% of P. radiata D. Don cones. In contrast, it was virtually absent from the cones of P. elliottii Engalm. et Vasey and P. taeda L. Botryosphaeria dothidea, on the other hand, was found to be common in all the Eucalyptus spp. tested, occurring in 93% of E. smithii R. T. Bak., 77% of E. camaldulensis Dehnh., 63% of E. grandis Hill ex Maid. and 57% of E. nitens (Deane et Maid.) Maid. leaves tested. The enigma of the rapid ingress of both these fungi in stressed or damaged trees might therefore be explained by their endophytic habit.