1. Plant Genome Mapping Laboratory, University of Georgia, Athens, Georgia 30602
2. Center for Genomics and Computational Biology, College of Life Sciences, Hebei United University, Tangshan, Hebei 063000, China
3. Mendel Biotechnology, Hayward, California 94545
4. Department of Horticulture, Chungnam National University, Daejeon, 305-764, South Korea