1. 1Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD 20742
2. 2BET Research Institute, Chung-Ang University, Anseong 456-756, Korea
3. 3Division of Biotechnology, Korea University, Seoul 136-713, Korea
4. 4Floriculture Research Division, National Institute of Horticultural and Herbal Science, Suwon 440-706, Korea