A Fusarium Head Blight Resistance Quantitative Trait Locus on Chromosome 7D of the Spring Wheat Cultivar Catbird

Abstract

ABSTRACTFusarium head blight (FHB) is a fungal wheat (Triticum aestivum L.) disease associated with yield and quality losses and mycotoxin grain contamination. Host plant resistance is the most economical and efficient way of control. However, novel sources of resistance are required. The objectives of this study were to identify quantitative trait loci (QTL) for type II resistance against FHB in the spring wheat cultivar Catbird, released by CIMMYT, and to find low cost molecular markers linked to these QTL. A population of 102 doubled haploid lines derived from the cross between Catbird and Milan (a FHB‐susceptible cultivar) was genotyped with 209 microsatellite markers and assessed by single floret inoculation in a greenhouse during 2007, 2008, and 2011. One significant QTL, named QFhs.inta‐7D, was detected on chromosome 7DS. Additionally, two minor and unstable QTL were also detected on chromosomes 3BS and 5DL. Favorable alleles for all three QTL were derived from Catbird. QFhs.inta‐7D peaked at simple sequence repeat (SSR) marker cfd14, flanked by markers barc128 and wmc702, and explained, on average, 20% of the phenotypic variation. The chromosomal region associated with FHB resistance in this work represents an interesting source of type II resistance and adds diversity to the FHB resistance gene pool. Stacking QFhs.inta‐7D with other QTL may achieve more acceptable levels of FHB resistance in new commercial cultivars. Once validated, markers linked to QFhs.inta‐7D could be used in marker‐assisted selection programs.