Mapping of Fusarium head blight resistance quantitative trait loci in winter wheat cultivar NC-Neuse

Fusarium head blight (FHB), primarily caused by Fusarium graminearum, can significantly reduce the grain quality of wheat (Triticum aestivum L.) due to mycotoxin contamination. The objective of this study was to identify quantitative trait loci (QTL) for FHB resistance in the moderately resistant soft red winter wheat cultivar NC-Neuse. A total of 170 recombinant inbred lines (RILs) from a cross between NC-Neuse and the susceptible cultivar AGS 2000 were evaluated in inoculated, mist-irrigated field nurseries. The lines were evaluated for FHB incidence (INC), severity (SEV), Fusarium-damaged kernels (FDK), and deoxynivalenol (DON) content in seven environments between 2011 and 2014. A 3,419 cM linkage map was developed based on 1839 simple sequence repeat (SSR), diversity array technology (DArT), and single nucleotide polymorphism (SNP) markers. Seven FHB resistance QTL on chromosomes 1A, 1B, 1D, 2A, 4A, 5B, and 6A were mapped. The QTL alleles conferring resistance on 1A, 1B, 2A, 4A, and 6A originated from NC-Neuse, while the alleles associated with resistance on 1D and 5B originated from AGS 2000. Quantitative trait loci effects ranged from 9 to 12% for INC, from 6 to 11% for SEV, from 8 to 20% for FDK, and from 6 to 18% for DON. The QTL on 5B co-localized with the Vrn-B1 locus. Kompetitive Allele-Specific PCR (KASP) assays were developed for each NC-Neuse QTL region. A preliminary test using these assays on recent Uniform Southern Winter Wheat Nursery (USWWN) entries indicated Qfhb.nc-1A, Qfhb. nc-1B, and Qfhb.nc-6A as likely the best candidates for use in marker-assisted selection.