Resistance to fusarium head blight and kernel damage in a winter wheat recombinant inbred line population
Fusarium head blight (FHB), primarily caused by Fusarium graminearum Schwabe [teleomorph: Gibberella zeae (Schwein.) Petch], is a devastating disease of wheat (Triticum aestivum L.), causing low yields and poor quality kernels that may be contaminated by the mycotoxin deoxynivalenol (DON). The objective of this study was to examine kernel damage resistance and to map quantitative trait loci (QTL) associated with FHB resistance in wheat. A population of 269 recombinant inbred lines (RILs) derived from a cross between IL94-1653 x Patton was evaluated for FHB resistance in greenhouse and field trials at Urbana, IL. The RIL population exhibited a broad and continuous distribution for all FHB resistance measurements. The correlation of disease severity with kernel damage was 0.78 in the greenhouse trial and 0.58 in the field trial. Grain DON concentration appeared to be environmentally affected, and correlated the most consistently with the ISK index, an index combining incidence, severity, and kernel damage measurements. Four severity QTL were identified on chromosomes 2B, 3B, 4B, and 6B, each explaining about 4 to 6% of the phenotypic variation. The same severity QTL were not detected in both the field and greenhouse trials. Three kernel damage QTL were identified on chromosomes 2B, 4B, and 6B, with the 4B QTL explaining 7 and 12.3% of the phenotypic variation for kernel damage in the greenhouse and field trials, respectively. This is the second report of a kernel damage QTL in this region of chromosome 4B, indicating that this QTL may contribute to reducing Fusarium-damaged kernels percentage.