Submitted to: Wheat Genetics International Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: June 5, 1998
Publication Date: N/A
Interpretive Summary: The winter wheat cultivar Triumph 64 has a unique pattern of resistance to wheat stem rust and is used to help differentiate races of stem rust. Because of a one to one relationship between genes for virulence in the stem rust pathogen and genes for resistance in wheat, it is important to know which gene or genes is present in wheats used as stem rust differentials. Differentiation of stem rust strains on a genetic basis is highly desirable. This research was done to determine the number of genes for resistance in a spring wheat derivative of Triumph 64, to determine the chromosomal location of the genes, and to establish their positional relationships to other known genes for resistance. An inheritance study showed that the Triumph 64 derivative has two genes for stem rust resistance. One of the genes is distant from the centromere in the long arm of chromosome 4A; it is at or near the same location as the known gene Sr7b. The location of the other gene was not determined, but chromosome 2B is a possible location.
Technical Abstract: A monosomic analysis of M-T64, a spring habit derivative of McNair 701/Triumph 64, indicated that chromosomes 4A, 2B, and 1D were possible carriers of genes for resistance to wheat stem rust culture 370c (Pgt QFMR). The F2 of the other 18 monosomic crosses indicated that M-T64 carries only two genes for resistance. We selected two lines, M-T64#1 and M-T64#8, each having a different single resistance gene from M-T64. The gene in M-T64#1 is independent of the centromere in chromosome 4AL and closely linked or allelic to Sr7b. The gene in M-T64#8 is not in chromosome 4A or 1D, but 2B is a possible location.