Figure 2.

Comparisons of EcoRI, HindIII, and DraI fragments among allopolyploids and their diploid progenitors. Southern-blot analysis of genomic DNA restricted with EcoRI, HindIII, and DraI revealed four types of relationships between S₁ B. napus genomes and their diploid progenitor genomes, B. rapa and B. oleracea. Each EL lane contains a bulked sample of DNA extracted from eight to 12 individual S₁ plants. A, Hybridization of EcoRI-restricted DNA with pW212 shows that the progeny of the S₀ synthetic allopolyploids have the same fragments as the diploid progenitors. Two of three polymorphic fragments are shown. B, Hybridization of HindIII-restricted DNA with pW220 shows that one line, EL600B, has lost a parental fragment. No novel fragment appears. All five fragments observed on the Southern blot are shown. C, Hybridization of pW241 to DNAs restricted with HindIII shows a parental fragment is absent from line EL9100A and a novel HindIII fragment appears. Two of three parental polymorphic fragments observed on the blot are shown. D, Hybridization of pW241 to DNAs restricted with HindIII shows that all donor genome fragments are present and there is a novel fragment in two lines, EL2700A and EL3400A. Two of three parental polymorphic fragments are shown.