[1] Botswana Int Univ Sci & Technol, Dept Biol Sci & Biotechnol, Private Bag 16, Palapye, Botswana
[2] Univ Pretoria, Forestry & Agr Biotechnol Inst, Dept Plant & Soil Sci, Pretoria, South Africa
[3] Biosci Eastern & Cent Africa Int Livestock Res Ins, POB 30709, Nairobi, Kenya