Fusarium Head Blight (FHB) is a devastating disease of small grains which infects the florets and reduce grain yield and quality. Effective integrated control strategies for combating FHB are those that also incorporate genetic resistance. Genetic resistance of wheat to FHB is due to the collective effects of numerous quantitative trait loci (QTL). Some resistance QTL have comparatively larger effects (such as the Sumai-3 derived germplasm); are well characterized and are widely used in breeding. Numerous other lesser resistance QTL with smaller individual effects are also known to occur in wheat; many of these are not well studied. The lesser QTL may nonetheless contribute useful levels of background resistance to QTL pyramids. This study aims to expand and diversify all available genetic variability for FHB resistance in advanced NDSU winter wheat (WW) breeding stock. The first study objective is to introgress the most recently available, “larger effect” resistance QTL, Fhb7 (derived from Thinopyrum elongatum by Cai and co-authors, 2022) through marker-aided, modified backcrosses. Two backcrosses to WW have been completed and B₂F₁ are currently being grown for doing marker and agrotype selection before completing the third set of backcrosses to WW. The second study objective is to search for useful and diverse sources of background genetic variability for FHB resistance in native winter wheat germplasm. A testcross analysis is being done that aims to measure and compare the general and specific combining abilities of 14 advanced WW lines that were used in testcrosses with four testers. One tester appears (marker data) to have both Fhb1 and Qfhs.ifa-5A; another has Fhb1 but only intermediate resistance, the third tester has intermediate background resistance, and the fourth tester is susceptible to FHB. The 56 F₁ hybrids and 18 parents will be point-inoculated in a greenhouse with mixed Fusarium graminearum isolates to measure FHB Type II resistance (disease spread). The magnitude and significance of combining ability effects will be calculated to determine which lines have the highest levels of background resistance and best complement the known resistance. Remnant F₁ seeds from superior hybrid combinations will be included in future breeding program crossing blocks. F₂ plants that were derived from the superior combinations will be re-evaluated for type II resistance and the best plants used to initiate single seed descent inbreeding.