1. Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI); University of Pretoria; Private bag x20 Pretoria 0028 South Africa
2. Camcore, Department of Forestry and Environmental Resources; North Carolina State University; Raleigh NC 27695-8008 USA
3. Mondi Forests, Trahar Technology Centre; P.O. Box 12 Hilton 3245 South Africa
4. Research School of Biology; Australian National University; 46 Sullivans Creek Road Canberra 2601 Australian Capital Territory Australia