Development and Molecular Cytogenetic Identification of Two Wheat- Roth 7M Chromosome Substitution Lines with Resistance to Fusarium Head Blight, Powdery Mildew and Stripe Rust.

Fusarium head blight (), powdery mildew, and stripe rust are major wheat diseases globally. Roth (UUMM, 2 = 4x = 28), a wild relative of common wheat, is valuable germplasm of disease resistance for wheat improvement and breeding. Here, we report the development and characterization of two substitution accessions with high resistance to powdery mildew, stripe rust and (W623 and W637) derived from hybrid progenies between and hexaploid wheat Chinese Spring (CS). Fluorescence in situ hybridization (FISH), Genomic in situ hybridizations (GISH), and sequential FISH-GISH studies indicated that the two substitution lines possess 40 wheat chromosomes and 2 chromosomes. Furthermore, compared that the wheat addition line parent W166, the 2 alien chromosomes from W623 and W637 belong to the 7M chromosomes of via sequential FISH-GISH and molecular marker analysis. Nullisomic-tetrasomic analysis for homoeologous group-7 of wheat and FISH revealed that the common wheat chromosomes 7A and 7B were replaced in W623 and W637, respectively. Consequently, lines W623, in which wheat chromosomes 7A were replaced by a pair of 7M chromosomes, and W637, which chromosomes 7B were substituted by chromosomes 7M, with resistance to , powdery mildew, and stripe rust. This study has determined that the chromosome 7M from exists genes resistant to and powdery mildew.