Alignment of homoeologous SBEIIa sequences used to design genome-specific forward (A) and reverse (B) primers. Primers are surrounded by boxes and genome specific polymorphisms are indicated in bold red. Exon 4 is in grey highlight and all other sequence corresponds to intron 4 (A) or intron 9 (B). Bold underlined bases in panel A indicate positions of introduced mismatches in primers relative to the genomic sequence. In/del events are represented by dashed lines except in the A genome of intron 9 (B) which has a large in/del event relative to the B and D genomes that is represented by bold red letters.