Mapping Fusarium Head Blight Resistance QTL in the Soft Wheat Cultivar Jamestown.

Fusarium Head Blight (FHB), a major disease in wheat (Triticum aestivum L.), caused by the pathogen Fusarium graminearum Schwabe, is most effectively controlled by deployment of cultivars having multiple pyramided resistance genes. Many resistance genes have been mapped in exotic and native wheat cultivars, including ‘Sumai 3’ and ‘Ernie’. The objective of this study is to identify quantitative trait loci (QTL) for FHB in the native soft red winter (SRW) wheat cultivar Jamestown. Seventy-seven Jamestown/LA97113UC-124 F_4:6 recombinant inbred lines (RILs) were evaluated for FHB incidence, severity, index, and concentrations of deoxynivalenol (DON) and nivalenol (NIV) mycotoxins in four environments (Arkansas, Georgia, Louisiana, and Virginia). Both public and proprietary single nucleotide polymorphism (SNP) markers were used to genotype the RILs at Monsanto Company. A 9k SNP platform was used and about 2,000 markers were identified in this population. A linkage map was constructed using Map Manager QTX, based on the consensus map provided by the Monsanto Company. Windows Cartographer (WinQTLCart version 2.5) was used to identify possible QTLs.  Fifty one putative QTLs for FHB were detected on all wheat chromosomes except for 4D, 5D, 6B, 6D, and 7D.  There were eight, six, eleven, four and nine QTLs associated with FHB incidence, severity, index, DON content and NIV content, respectively. The R² values for the QTLs ranged from 8.9% to 61.9%.  Among the 51 QTLs, 18 were consistent in that a given QTL controlled more than one FHB trait or the QTL was observed across environments.  These consistent QTL were located on chromosomes 1A, 1B, 1D, 2A, 3B, 4A, 5A, 5B, 6B, 6D, 7A, and 7B.  The QTLs identified in the first year will be verified using a second year of phenotypic data.  Consistent novel FHB resistance QTL in Jamestown can be used in marker-assisted breeding.