Affiliation: | (1) Centre for Plant Breeding, PO Box 16, NL-6700 AA Wageningen, The Netherlands;(2) Centre for Reproduction Research (CPRO-DLO), PO Box 16, NL-6700 AA Wageningen, The Netherlands;(3) Present address: Agrotechnological Research Institute (ATO-DLO), Haagsteeg 6, PO Box 17, NL-6700 AA Wageningen, The Netherlands |