1. Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria , Pretoria 0028, South Africa
2. Biotechnology Platform, Agricultural Research Council (ARC) , Pretoria 0110, South Africa
3. Department of Zoology and Entomology, Forestry and Agricultural Biotechnology Institute, University of Pretoria , Pretoria 0028, South Africa