LAUSR

ND2710 is a hard red spring wheat line with a very high level of resistance to Fusarium head blight (FHB). It was selected from the progeny of a cross between ND2603 (an advanced breeding line derived from the Sumai 3/Wheaton cross) and Grandin (a spring wheat cultivar). The FHB resistance of ND2710 is presumably derived from Sumai 3 because the other parents (Grandin and Wheaton) are very susceptible to FHB. To identify and map the quantitative trait loci (QTL) for FHB resistance in ND2710, we developed a mapping population consisting of 233 recombinant inbred lines (RILs) from the cross between ND2710 and the spring wheat cultivar Bobwhite. These RILs along with their parents and checks were evaluated for reactions to FHB in three greenhouse experiments and one field experiment during 2013 to 2014. The population was also genotyped with the wheat 90K iSelect single-nucleotide polymorphism (SNP) assay, and a genetic linkage map was developed with 1,373 non-cosegregating SNP markers, which were distributed on all 21 wheat chromosomes spanning 914.98 centimorgans of genetic distance. Genetic analyses using both phenotypic and genotypic data identified one major QTL (Qfhb.ndwp-3B) on the short arm of chromosome 3B, and three minor QTL (Qfhb.ndwp-6B, Qfhb.ndwp-2A, and Qfhb.ndwp-6A) on 6B, 2A, and 6A, respectively. The major QTL on 3B was detected in all experiments and explained 5 to 20% of the phenotypic variation, while the three minor QTL on 6B, 2A, and 6A explained 5 to 12% phenotypic variation in at least two experiments, except for Qfhb.ndwp-2A, which was only detected in the field experiment. Qfhb.ndwp-3B and Qfhb.ndwp-6B were mapped to the genomic regions containing Fhb1 and Fhb2, respectively, confirming that they originated from Sumai 3. The additive effect of the major and minor QTL may contribute to the high level of FHB resistance in ND2710. The SNP markers closely linked to the FHB resistance QTL will be useful for marker-assisted selection of FHB resistance in wheat breeding programs.