Transfer of Fusarium Head Blight Resistance from Thinopyrum elongatum to bread wheat cultivar Chinese Spring

The diploid form of Tall Wheatgrass, Thinopyrum elongatum (Host) D. R. Dewey (2n = 2x = 14, EE genome) has a high level of resistance to Fusarium head blight. The symptoms do not spread beyond the inoculated floret following point inoculation. Using the series of E genome chromosome additions in a bread wheat cultivar Chinese Spring (CS) background, the resistance was found to be localized to the long arm of chromosome 7E. CS mutant ph1b was used to induce recombination between chromosome 7E, present in the 7E(7D) substitution and homoeologous wheat chromosomes. Multivalent chromosome associations were detected in BC1 hybrids attesting to the effectiveness of the ph1b mutant. Genetic markers specific for chromosome 7E were used to estimate the size of the 7E introgression in the wheat genome. Using single sequence repeat (SSR) markers specific for homoeologous wheat chromosome 7, introgressions were detected on wheat chromosomes 7A, 7B and 7D. Some of the introgression lines were resistant to Fusarium head blight.