Identification of a Novel Fusarium Head Blight Resistance Quantitative Trait Locus on Chromosome 7A in Tetraploid Wheat.

ABSTRACT Fusarium head blight (FHB) caused by Fusarium graminearum is one of the most destructive diseases of durum (Triticum turgidum sp. durum) and common wheat (T. aestivum). Promising sources of FHB resistance have been identified among common (hexaploid) wheats, but the same is not true for durum (tetraploid) wheats. A previous study indicated that chromosome 7A from T. turgidum sp. dicoccoides accession PI478742 contributed significant levels of resistance to FHB. The objectives of this research were to develop a genetic linkage map of chromosome 7A in a population of 118 recombinant inbred lines derived from a cross between the durum cv. Langdon (LDN) and a disomic LDN-T. turgidum sp. dicoccoides PI478742 chromosome 7A substitution line [LDN-DIC 7A(742)], and identify a putative FHB resistance quantitative trait locus (QTL) on chromosome 7A derived from LDN-DIC 7A(742). The population was evaluated for type II FHB resistance in three greenhouse environments. Interval regression analysis indicated t...