Synthesis of an FHB-resistant durum disomic alien addition line with a pair of diploid wheatgrass chromosomes

Abstract

Durum wheat ( Triticum turgidum L., 2 n = 4 x = 28; AABB genomes) is an important cereal crop widely used for human consumption. Fusarium head blight (FHB), or scab, caused by the fungus Fusarium graminearum Schwabe, is a serious disease of durum wheat. Current durum cultivars have very little or no FHB resistance. A wild relative, diploid wheatgrass Lophopyrum elongatum (Host) A. Love (2 n = 2 x = 14; EE genome) is an excellent source of resistance. By crossing durum wheat with L. elongatum we produced F 1 hybrids that were male sterile. By backcrossing the F1 hybrids to the durum parent, followed by selfing, we obtained several fertile hybrid derivatives with FHB resistance. We isolated a disomic addition line (2 n = 28 + 2) with a pair of L. elongatum chromosomes. This alien addition line is meiotically regular and hence reproductively stable. The addition line is FHB-resistant with a mean infection of 6.5%, while the parental durum has 80% infection. Using various biochemical and molecular techniques ...