Introgression of Elymus trachycaulus chromatin into common wheat

A number of wheat-Elymus trachycaulus (2n = 4x = 28, genomically (SSHHt)-S-t-H-t-H-t) chromosome addition, substitution, and translocation lines were isolated from the derivatives of an E. trachycaulus x wheat hybrid. Eighteen out of a total of 28 chromosome arms of E. trachycaulus were recovered in the addition lines. The genomic affinity of individual E. trachycaulus chromosomes was analysed by comparative chromosome banding and in situ hybridization using genome-specific repetitive DNA sequences as probes. The homoeology of the E. trachycaulus chromosomes added to wheat was determined by storage protein, isozyme, and restriction fragment length polymorphism analysis. Alloplasmic wheat-E, trachycaulus chromosome additions were isolated which only involved chromosome 1H(t) and 1S(t) that carry fertility restoration gene Rf-H(t)1 and Rf-S(t)1, respectively. Based on the results of production and characterization of a wheat-E, trachycaulus 5H(t)(5B) substitution line, it is likely that some wheat chromosomes can be well compensated genetically by E. trachycaulus chromosomes. Several spontaneous wheat-E, trachycaulua chromosome translocation lines were detected. All the translocation lines involved either 1H(t) or 1S(t). To estimate the potential of recombination between wheat and E. trachycaulus chromosomes, a backcross population derived from a plant which was double monosomic for chromosomes 7A and 7AL.7AS-(ISS)-S-t and a ph1b gene was developed. The plants from this population were analysed for 1S(t)-specific genetic markers and no recombinant was recovered.