Molecular Charaterization of Fusarium Head Blight Resistance from Elymus repens Introgressed Into Bread Wheat

A cross was made of Elymus repens onto wheat cultivar Crocus and BC1 progeny were advanced to BC1F7 by single seed descent. Sixteen lines were selected based on agronomic performance and evaluated in an FHB epiphytotic nursery. Eight lines with resistance to FHB were selected. GISH analysis revealed many complex chromosome numbers and recombinations in the derived lines. The least complex recombinant line was P1142-3-1 with 42 chromosomes with one pair of chromosomes showing telomeric recombinants in both arms. This wheat chromosome was identified as 3D by applying several SSR markers from every arm of every wheat linkage group and noting those that provided no signal. Lines with single telomeric recombinants were produced by additional crosses to Crocus and inoculation with FHB spores. It was found that the resistance was contributed by the recombinat on the long arm of chromosome 3D. These lines had minimal linkage drag and should be amenable to applications in breeding for disease resistance