An individual plant, line 0-123-1-1 with the chromosome number 2n = 42 was obtained in the BC₃F₄progeny of a cross between a wheat 1BL.1RS translocation line 48112 and wheat–Thinopyrum ponticumpartial amphiploid BE-1. Molecular markers specific for 1RS,Glu-B3, and theT. ponticumgenome specific marker SCAR₉₈₂revealed that the line was trigeneric having alien chromatin from bothT. ponticumand rye. Resistance tests with mixed races ofBlumeria graminisf. sp.triticiand an individual race ofPuccinia striiformisat the seedling and adult stages revealed that 0-123-1-1 was immune to powdery mildew and stripe rust for the whole growth period. High levels of disease resistance and good and stably agronomic traits make the 0-123-1-1 line a good germplasm for breeding in wheat.