PCR-based marker profiles of plants from <i>B</i>. <i>distachyon</i>, <i>B</i>. <i>stacei</i>, their derived F1 interspecific hybrids and synthetic <i>B</i>. <i>hybridum (</i>S1 and S2 generations) as well as natural <i>B</i>. <i>hybridum</i>, and mixtures of equal amounts of parental DNAs (MPV1 and MPV2).

<p>(A) Marker Bd2-28 showing no polymorphism between <i>B</i>. <i>distachyon</i> (Bd21 and Bd3-1) and <i>B</i>. <i>stacei</i> (ABR114 and Bsta5) parent lines and no change in F1, S1 and S2 synthetic allopolyploid. (B) Marker Bd3-11 showing a presence⁄absence polymorphism (PAP) with a band in <i>B</i>. <i>stacei</i> and no band in <i>B</i>. <i>distachyon</i>. All F1, S1 and S2 plants have a band that is the same size as the <i>B</i>. <i>stacei</i> band. (C) Marker Bd5-14 exhibits allele size polymorphism (ASP+) between <i>B</i>. <i>distachyon</i> and <i>B</i>. <i>stacei</i>, with both parental alleles amplified in MPVs, F1, S1, S2, and natural <i>B</i>. <i>hybridum</i>. (D) Marker Bd1-26 exhibiting allele size polymorphism (ASP-) between <i>B</i>. <i>distachyon</i> (Bd21 and Bd3-1) and <i>B</i>. <i>stacei</i> (ABR114 and Bsta5). In this case, while the parents have different sized bands, the <i>B</i>. <i>distachyon</i> allele is not amplified in MPVs (red arrows), natural <i>B</i>. <i>hybridum</i> or the F1, S1 and S2 generations. Absence of the <i>B</i>. <i>distachyon</i> allele is most likely due to competition for PCR amplification between progenitor alleles and not from DNA rearrangements. L: 50 bp ladder (Invitrogen, Carlsbad, CA, USA). MPV1; Mixture of DNA from Bd21 and ABR114. MPV2: Mixture of DNA from Bd3-1 and Bsta5.