Figure 4.

Plants containing the Brrga1-d mutation are dwarf. A, Arabidopsis ecotype Wassilewskija is dwarfed by expressing a mutated Atrga transgene with the Brrga1-d mutation (Atrga-d). Primary transformants (T₁ plants) were allowed to set seed (by self-pollination), and progeny (T₂ plants) from two independent transgenic lines (2D and 3D) are shown. Left, T₂ plants lacking the transgene. Right, T₂ plants that are homozygous for the transgene. B, Hybrid oilseed rape is dwarfed by having the Brrga1-d allele transferred by interspecific hybridization of B. rapa and B. oleracea, embryo rescue, chromosome doubling, and backcrossing to the parents of a hybrid combination (A. Muangprom, I. Mauriera, and T.C. Osborn, unpublished data). Left, BrRGA1 wild-type hybrid. Right, Brrga1-d semidwarf hybrid.