1. Department of Genetics, North Carolina State University, Raleigh, North Carolina 27695
2. U.S. Department of Agriculture, Agricultural Research Service, Raleigh, North Carolina 27695
3. Department of Food Science and Technology, University of California, Davis, California 95616
4. Department of Crop Sciences, University of Illinois, Urbana, Illinois 61801
5. Department of Crop Science, North Carolina State University, Raleigh, North Carolina 27695
6. U.S. Department of Agriculture, Agricultural Research Service and Department of Plant Breeding, Cornell University, Ithaca, New York 14850