Key message Heterogeneous Lr34 genes for leaf rust in winter wheat cultivar ‘Duster’ and KASP markers for allelic variation in exon 11 and exon 22 of Lr34. Abstract Wheat, Triticum aestivum (2 n = 6 x = 42, AABBDD), is a hexaploid species, and each of three homoeologous genomes A, B, and D should have one copy for a gene in its ancestral form if the gene has no duplication. Previously reported leaf rust resistance gene Lr34 ha...