1. Laboratory of Plant Physiology (N.C.-Q., H.B., J.J.B.K.), Wageningen University & Research centre Plant Breeding (A.A., C.M., C.W.B.B., R.G.F.V.), and Laboratory of Genetics (J.J.B.K.), Wageningen University, 6708 PB Wageningen, The Netherlands; Plant Research International, Wageningen University & Research centre, 6708 PB Wageningen, The Netherlands (R.M.); Centre for BioSystems Genomics, 6700 A