Evaluation of fusarium head blight resistance in tetraploid wheat (Triticum turgidum L.)

Durum wheat (Triticum turgidum L. subsp. durum) production in North America in recent years has been seriously threatened by epidemics of Fusarium head blight (FHB), caused mainly by Fusarium graminearum Schwabe [teleomorph Gibberella zeae (Schw.) Petch]. Deployment of FHB-resistant cultivars has been considered the most effective and cost-efficient strategy to combat this disease; however, progress in developing FHB-resistant durum wheat cultivars has been hindered by a lack of effective sources of resistance. The objective of this study is to identify tetraploid wheat germplasm that could be used to enhance FHB resistance in durum wheat. We evaluated FHB reactions in 376 accessions of five cultivated subspecies of T turgidum, including Persian wheat [T turgidum subsp. carthlicum (Nevski) A. Love and D. Love], cultivated emmer wheat [T turgidum subsp. dicoccum (Schrank ex Schubler) Thell], Polish wheat [T turgidum subsp. polonicum (L.) Thell.], Oriental wheat [T turgidum subsp. turanicum (Jakubz.) A. Love and D. Love], and Poulard wheat (T turgidum L. subsp. turgidum). We used point inoculation to evaluate resistance to the spread of infection over three greenhouse seasons and used the grain inoculum method of inoculation to evaluate putatively resistant accessions in two field locations. Preliminary evaluation data showed that 16 T turgidum subsp. carthlicum and 4 T turgidum subsp. dicoccum accessions consistently exhibited resistance or moderate resistance to FHB. These accessions likely carry genetic resistance to FHB and could be used directly in breeding programs to enhance FHB resistance in durum wheat.