Fig. 2.

Synteny, partial retention, and evolutionary analyses of HPT2. A The synteny of HPT1 and HPT2 in common Pales species using barley genome as references (see Additional file 3 for gene ids). B Presence of and absence of HPT2 in barley pangenome (20 lines), representative wild emmer (20 lines), bread wheat pangenome (16 lines). C Bar charts displaying the negative correlation of HPT2 retention rates with the ploidy level and HPT1 copy number in barley, wild emmer, and bread wheat. D The presence and absence of HPT2 in wild barley lines collected from the north-facing slope (NFS) and south-facing slope (SFS) of the Evolution Canyon in Israel (Fig. reproduced from reference [46]). E Geographical map displaying the presence (red) and absence (yellow) of HPT2 in the 300 barley WGS lines and 109 Tibetan barley lines (distinguished in oval). F ML phylogeny of HvHPT2s in barley pangenome lines based on SNP variations (Additional file 4). HPT2 from wild emmer (TRIDC2Bv2G208200, highlighted in green) was used as outgroup to resolve the evolutionary origin of HvHPT2 in barley. HvHPT2s in barley lines near the Fertile Crescent in Israel (red; including Israel, Jordan, Lebanon, Syria, Turkey, and Iraq), Tibetan barley lines (blue), other wild barley (black) and domesticated barley (gray) were distinguished