Molecular Characterization of Fusarium Head Blight Resistance in the U.S. Adapted Soft Red Winter Wheat Germplasm Lines and Cultivars.

Several U.S. sources of resistance to Fusarium head blight (FHB) have been identified and studied in adapted soft red winter (SRW) wheat germplasm lines or cultivars.  Quantitative traits loci associated with FHB resistance have been mapped for FHB severity in greenhouse and field experiments and for FHB incidence, Fusarium damaged kernels, and deoxynivalenol (DON) accumulation in inoculated mist-irrigated field studies. Three mapping populations were screened under multiple environments including greenhouse, field nurseries, and natural field conditions in different years and locations.  Major common QTL were found in two SRW wheat cultivars, Ernie and Massey, on chromosome 2DS, 3BL, 4BS and 4DS, while unique QTL were identified in the elite breeding line VA00W-38.  Some QTL identified in these sources mapped to the same chromosome regions as those identified in other U.S. and/or European wheat germplasm, while some QTL were only prevalent in SRW wheat lines from the U.S.  Interactions between QTL for FHB resistance and the environment were analyzed to determine the stability of effects of various QTL across different environments.