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<p>Abstract</p> <p>Background</p> <p>The <it>APETALA2</it>-like genes form a large multi-gene family of transcription factors which play an important role during the plant life cycle, being key regulators of many developmental processes. Many studies in <it>Arabidopsis </it>have revealed that the <it>APETALA2 </it>(<it>AP2</it>) gene is implicated in the establishment of floral meristem and floral organ identity as well as temporal and spatial regulation of flower homeotic gene expression.</p> <p>Results</p> <p>In this work, we have cloned and characterised the <it>AP2</it>-like gene from accessions of <it>Hordeum chilense </it>and <it>Hordeum vulgare</it>, wild and domesticated barley, respectively, and compared with other <it>AP2 </it>homoeologous genes, including the Q gene in wheat. The <it>Hordeum AP2</it>-like genes contain two plant-specific DNA binding motifs called AP2 domains, as does the Q gene of wheat. We confirm that the <it>H. chilense AP2</it>-like gene is located on chromosome 5H^ch. Patterns of expression of the <it>AP2</it>-like genes were examined in floral organs and other tissues in barley, wheat and in tritordeum amphiploids (barley × wheat hybrids). In tritordeum amphiploids, the level of transcription of the barley <it>AP2</it>-like gene was lower than in its barley parental and the chromosome substitutions 1D/1H^chand 2D/2H^chwere seen to modify <it>AP2 </it>gene expression levels.</p> <p>Conclusion</p> <p>The results are of interest in order to understand the role of the <it>AP2</it>-like gene in the spike morphology of barley and wheat, and to understand the regulation of this gene in the amphiploids obtained from barley-wheat crossing. This information may have application in cereal breeding programs to up- or down-regulate the expression of <it>AP2</it>-like genes in order to modify spike characteristics and to obtain free-threshing plants.</p>