Transfer of Fusarium Head Blight Resistance QTL from PI277012 to Winter Wheat

Abstract Fusarium head blight (FHB) causes substantial wheat grain yield and quality losses. Host resistance is conditioned by numerous small effect quantitative trait loci (QTL) that are strongly affected by the environment and genetic background. Genetic resistance is partial but crucial for effective, integrated management of the disease. Qfhb.rwg-5A.1 and Qfhb.rwg-5A.2 (PI277012) are two recently discovered resistance QTL that also occur in spring wheat GP80 (PI277012 derivative). To transfer the PI277012 resistance to hard winter wheat (HWW), GP80 was first crossed with Novus-4. The F1 hybrid was crossed with SY Monument, following which marker-selected progeny were crossed with, and backcrossed to, ND Noreen. To identify likely resistance carriers among the 22 F1 of the ND Noreen cross, simple sequence repeat (SSR) markers, Illumina 90K single nucleotide polymorphism (SNP) haplotypes and greenhouse FHB Type II resistance tests were done. Likely homozygotes for Qfhb.rwg.5A.1 and Qfhb.rwg.5A.2, were selected and backcrossed to ND Noreen. In the B1F1, 131 plants were evaluated for SNP haplotypes, SSR markers and FHB resistance. Nine B1F2:3 lines were derived, and their resistance confirmed in a third greenhouse FHB trial. The results suggested that eight lines had resistance comparable to GP80 with the Qfhb.rwg-5A.2 markers occurring in all eight and the Qfhb.rwg-5A.1 markers occurring in four lines. The eight selections constitute a valuable HWW resistance breeding resource.