Evaluation of Fusarium Head Blight Resistance QTL On Agronomic and Quality Traits of Soft Red Winter Wheat Populations.

Resistance to Fusarium head blight (FHB), caused by Fusarium graminearum Schwabe [telomorph: Gibberella zeae Schwein.(Petch)], is a quantitative trait. FHB is recognized as one of the most destructive diseases of wheat (Triticum aestivum L. and T. durum L.) and barley (Hordeum vulgare L.) worldwide. Breeding for FHB resistance must be accompanied by selection for desirable agronomic traits. The objectives of this study are (i) to explore the utility of two important FHB resistance quantitative trait loci (QTL) in different genetic backgrounds and (ii) to validate a Near Infrared Reflectance (NIR) based method for Fusarium damaged kernels (FDK), deoxynivalenol (DON) and quality traits prediction. Donor parents with two FHB resistance QTL Fhb1 and QFhs.nau-2DL were crossed to four adapted SRW wheat lines to generate backcross and forward-cross progeny. F₂ individuals were genotyped and assigned to 4 different groups according to presence/ absence of resistance alleles at both QTL. The effectiveness of these QTL in reducing FHB in F₂derived lines was assessed in a misted, inoculated scab nursery in a 2-year study. Traits measured included FHB rating (1-9), severity (%), incidence (%), FHB index (severity * incidence), FDK (%) and DON concentration (ppm). The populations were also grown in yield trials in two locations in Kentucky in 2011 and 2012. NIR was used to predict FDK, DON and milling and baking quality and the results were compared with actual values. Fhb1 and QFhs.nau-2DL often reduced disease. The number of lines that exceeded the mean yield of 4 different commercial checks ranged from 12.5% to 57.8% of lines across the 7 populations. In 6 of 7 populations, the backcross derived lines were superior in yield than forward-cross derived progeny, suggesting that although these lines have a scab resistant parent with poor agronomic performance, one backcross is enough to restore high yield potential.