1. Department of Microbiology and Plant Pathology; Forestry and Agricultural Biotechnology Institute (FABI); University of Pretoria; Pretoria South Africa
2. Department of Genetics; Forestry and Agricultural Biotechnology Institute (FABI); University of Pretoria; Pretoria South Africa
3. Swiss Federal Research Institute for Forest; Snow and Landscape WSL; CH-8903 Birmensdorf Switzerland