Figure 1.

Pedigree of lines used in this study. Plants of two double-haploid genotypes (Brassica oleracea, TO1000C and Brassica rapa, IMB218A) were crossed to generate a population of 49 hybrid (CA) plantlets. Eight of these plantlets spontaneously generated putative allopolyploid tissues; 39 plantlets were treated with colchicine. Two hybrid plantlets (EL570 and EL780) were chimeric and used to generate colchicine-doubled and spontaneously doubled allopolyploids. Thus, the number of putative S₁ allopolyploids is 2 greater than the number of hybrid plants (see text). Allopolyploidy was assessed using molecular markers, flow cytometry, pollen fertility, and morphological characteristics. Allopolyploid S₀ plants were self pollinated to generate S₁ progeny, and eight to 12 plants were grown from each family for a bulk analysis.