Identification and molecular mapping of quantitative trait loci for Fusarium head blight resistance in emmer and durum wheat using a single nucleotide polymorphism-based linkage map

Abstract

Fusarium head blight (FHB), caused by Fusarium graminearum, threatens durum wheat (Triticum turgidum subsp. durum) production in many durum-growing regions. It is critical to identify useful sources of FHB resistance for durum wheat. A domesticated emmer wheat (T. turgidum subsp. dicoccum) accession, PI 41025, was previously shown to be moderately resistant to FHB. This study aimed to identify quantitative trait loci (QTL) associated with FHB resistance in PI 41025. A population of 200 recombinant inbred lines were developed from a cross between the durum cultivar ‘Ben’ and PI 41025 and evaluated for reactions to F. graminearum in one field nursery and three greenhouse experiments. The disease severity data and a single nucleotide polymorphism marker-based linkage map from this population were used for QTL analysis. The results showed that one QTL on chromosome 2A from Ben and one QTL each on 3A and 5A from PI 41025 were associated with FHB resistance. The 2A and 3A QTL each explaining 8 % of the phenotypic variation were detected only in the greenhouse experiments. The QTL on 5A, which mapped near the domestication gene Q, explained 11 and 35 % of phenotypic variation in greenhouse and field evaluations, respectively. The identification of the 2A QTL from Ben confirmed the presence of FHB resistance in North Dakota durum cultivars, which have been successfully used for developing new cultivars with improved FHB tolerance. This study indicates that combining the QTL from related tetraploid species with native durum QTL will be useful for improving FHB resistance in durum.