1. Biotechnology Dep.; South African Sugar Association Exp. Stn.; Private Bag X02 Mount Edgecombe 4300 South Africa
2. Institute for Plant Biotechnology; University of Stellenbosch; Private Bag X1 Matieland 7602 South Africa
3. Institute for Plant Biotechnology; Univ. of Stellenbosch; Private Bag X1 Matieland 7602 South Africa