Inheritance and characterization of the new and rare gene Rph25 conferring seedling resistance in Hordeum vulgare against Puccinia hordei

In this study, we characterized and mapped a new and rare resistance gene ( Rph FT ) in the Chinese barley variety ‘Fong Tien’. Rph FT , a dominant gene, was mapped to chromosome 5 HL at a genetic position of 142.1 cM using DA rT‐seq markers. The gene was also confirmed to be present in Australian cultivar ‘Yagan’ based on allelic tests, and likely ‘Lockyer’ based on multipathotype tests. The genetic studies also confirmed the presence of Rph12 in Australian cultivar ‘Baudin’. Rph12 is also located on chromosome 5 HL close to Rph FT , and the two loci were confirmed to be independent. Gene Rph FT is of limited breeding value because it is effective to only one pathotype of P. hordei , 220P+ + Rph13 in Australia; nevertheless, it may play a role in controlling leaf rust if used in combination with other Rph genes. The locus symbol Rph25 is recommended for Rph FT in accordance with the rules and numbering system of barley gene nomenclature.