1. Institute of Biotechnology, Addis Ababa University, P. O. Box 1176, Addis Ababa, Ethiopia
2. Salale University, Fitche, Ethiopia
3. Department of Plant Breeding, Swedish University of Agricultural Sciences, P. O. Box 101, Alnarp 23053, Sweden
4. Department of Microbial, Cellular and Molecular Biology, Addis Ababa University, Addis Ababa, Ethiopia