Exotic scab resistance quantitative trait loci effects on soft red winter wheat

Fusarium head blight (FHB), caused by Fusarium graminearum, of wheat (Triticum aestivum L.) is a disease that periodically strikes the mid- Atlantic region of the United States. Breeding for resistant wheat varieties is an effective method of disease control. The objective of this study was to evaluate the effects of exotic FHB resistance quantitative trait loci (QTL), singly and in combination, on FHB resistance in soft red winter wheat (SRWW). Three FHB resistance QTL on chromosomes 3BS (Fhb1), 2D, and 5A were introgressed from nonadapted Chinese cultivar Ning7840 into the adapted SRWW cultivar McCormick. Eight near-Isogenic lines (NIL) were developed by marker-assisted backcrossing. The NIL that combined 3BS and 2DL expressed the highest resistance and lowest deoxynivalenol (DON) content in four environments that included three field and one greenhouse studies. These results indicate that the combination of just two QTL (3BS and 2DL) would be useful to breed for improved FHB resistance in SRWW in the mid-Atlantic region.