1. Department of Genetics; Forestry and Agricultural Biotechnology Institute (FABI); University of Pretoria; Pretoria 0002 South Africa
2. Department of Microbiology and Plant Pathology; Forestry and Agricultural Biotechnology Institute (FABI); University of Pretoria; Pretoria 0002 South Africa
3. Forest Health Dynamics Laboratory; School of Forestry and Wildlife Sciences; Auburn University; Auburn AL 36849 USA