Affiliation: | Plant Molecular Biology Laboratory, Department of Biotechnological Sciences, Agricultural University of Norway, P.O. Box 5051, N-1432 Ås, Norway; Plantech Research Institute, 1000 Kamoshida, Midori- ku, Yokohama 227, Japan; Cell and Tissue Culture Group NLVF, Department of Biology and Nature Conservation, Agricultural University of Norway, P.O. Box 5014, N-1432 Ås, Norway |