Development of gene-based markers for the identification of wheat-rye translocations possessing 1RS

Wheat-rye translocations carry valuable genes for pest resistance; this has led to their incorporation into wheat varieties. To develop gene-based 1RS specific markers, expressed sequence tags (ESTs) mapped to the short arm of wheat homoeologous group 1 were downloaded from a public database. ESTs and mature transcript sequences of nine species from the Poaceae family were BLASTed to perform comparative analysis. ESTs selected using the BLAST tool were used for primer design. The target sequences of primers were expected to exist in most species of the Poaceae family, and therefore, cross-species primers were designed. Amplicons obtained using these cross-species primer pairs were sequenced in the 1BL.1RS near-isolines (OK91G113' [1BL.1RS] and OK91G114' [non-translocation]), Chinese Spring' and Petkus' rye (1RS donor for 1BL.1RS translocations). Through in silico analysis and primer validation, we were able to develop four 1RS-specific markers and these markers were confirmed with analysis involving 15 1RS translocation lines.