Production and Molecular Cytogenetic Characterization of a Durum Wheat-Thinopyrum elongatum 7E Disomic Addition Line with Resistance to Fusarium Head Blight.

Wheatgrass, Thinopyrum elongatum (2n = 2x = 14, EE), is an important wild relative of wheat with many excellent traits, including resistance to Fusarium head blight (FHB), that can be used for durum wheat improvement. Through hybridization of the durum cultivar "Langdon" with the amphiploid 8801 (AABBEE), a disomic alien addition line (2n = 30) with a pair of Th. elongatum 7E chromosomes was obtained and confirmed using chromosome-specific molecular markers of Th. elongatum and genomic in situ hybridization (GISH). This line is meiotically and reproductively stable, generally forming 15 bivalents at meiosis including 14 pairs from Langdon and 1 from Th. elongatum with 2 chiasmata each as revealed by GISH analysis. At the adult growth stages under field conditions, this addition line shows high resistance to FHB, with less than 16% infection on visual observation in 2 years (2014 and 2015). This addition line is shorter in height and has narrower leaves and shorter spikes as compared to its parent Langdon. So the linkage group 7E might be a further source of wheat improvement by targeted introgression approaches.