Fig. 2. Transgene expression analysis over three successive generations. Average NPTII protein concentrations in relation to total soluble protein are shown for 12 T₀ plants (samples 1-12); 4 T₁ plants selected on 400 mg L^–1 kanamycin (samples 21-24); and 28 T₂ plants, 11 of which were selected on kanamycin at 300 mg L^–1 (samples 25-35), 9 on 400 mg L^–1 kanamycin (samples 36-44), and 8 selected on 500 mg L^–1 kanamycin (samples 45-52). An untransformed plant (ut) was used as a negative control. Histochemical GUS assay results are denoted below the corresponding sample number and were scored as either positive (+) or negative (–). Vertical bars indicate the standard error.