Fusarium head blight (FHB), caused by Fusarium graminearum Schwabe, is one of the most devastating diseases of wheat (Triticum aestivum L.). A synthetic hexaploid wheat line Largo, developed from a cross between the durum wheat (T. turgidum L. ssp. durum (Desf.) Husn.] variety ‘Langdon’ and the Aegilops tauschii Cosson accession PI 268210, was previously found to have a high level of resistance. This study was conducted to identify resistance quantitative trait loci (QTL) using a population of 188 recombinant inbred lines (RILs) from a cross between Largo and the susceptible wheat line ND495. The RILs were evaluated for Type II resistance in two greenhouse seasons and two field environments. The disease severity and existing 90K SNP marker data were used for QTL analysis, which led to the identification of six QTL on chromosomes 1D, 2D, 5B, and 7D. Four QTL (QFhb.rwg-1D, -5B, -7D.1, and -7D.3) with minor effects were derived from Largo, whereas two (QFhb.rwg-2D and -7D.2) with larger effects were from ND495. Five QTL collocated or overlapped with previously reported QTL, whereas QFhb.rwg-1D located in a region with no known QTL, suggesting that it is a novel QTL. QFhb.rwg-2D was the only QTL detected in all four environments and it is likely the same QTL as the major and stable 2D QTL present in many wheat varieties. Because QFhb.rwg-2D was not previously identified in adapted hard red spring wheat germplasm, its detection in ND495 will facilitate its utilization in hard red spring breeding programs. The QTL detected from the resistant and susceptible parents enhance our understanding of FHB resistance expression and provide new resources for improving FHB resistance in wheat, further suggesting that an effective strategy to improve FHB resistance is to pyramid multiple resistance QTL while also eliminating susceptibility genes.

ACKNOWLEDGEMENT AND DISCLAIMER

This material is based upon work supported by the Agreement No. 59-0206-2-ARS (USWBSI). This is a cooperative project with the U.S. Wheat & Barley Scab Initiative. This research was also supported in part by an appointment to the Agricultural Research Service (ARS) Research Participation Program administered by the Oak Ridge Institute for Science and Education (ORISE) through an interagency agreement (contract number DE-SC0014664) between the U.S. Department of Energy (DOE) and the U.S. Department of Agriculture (USDA). All opinions expressed in this paper are the author's and do not necessarily reflect the policies and views of USDA, DOE, or ORAU/ORISE.