Figure 2. Frequency distribution of the number of selected individuals in the F₁ generation of the topcross (TCF₁) (A) and doubled haploid lines (DHs) (B). The parents for the topcross were HM14BS, Sunstate, and Silverstar+tin. There were 500 individuals grown in the TCF₁, 50 seeds were taken from each selected TCF₁ individual to produce the F₂ generation of the topcross (TCF₂), and 50 DHs were produced from each selected TCF₂ individual. In the TCF₁ generation, homozygous selection was applied for Rht-B1a and Glu-B1i, and enrichment selection for Rht8, Cre1, and tin. In the TCF₂ generation, homozygous selection was applied for Rht8, and enrichment selection for remaining target alleles. In DHs, only the target genotype was selected.