Durum wheat genetic stocks involving chromosome 1E of diploid wheatgrass: resistance to Fusarium head blight

Abstract

Durum wheat (Triticum turgidum L., 2n = 4x = 28; AABB genomes) is the preferred wheat for preparing pasta products. Current durum cultivars have little resistance to Fusarium head blight (FHB), or scab, a ravaging fungal disease. In our Durum Germplasm Enhancement (DGE) project, we previously showed that chromosome 1E of diploid wheatgrass Lophopyrum elongatum (Host) A. Love (2n = 2x = 14; EE genome) is an excellent source of FHB resistance. Through hybridization of this grass with the durum cultivar Langdon, coupled with manipulation of chromosome pairing and selection, we added the chromosome 1E pair into the durum genome and produced a fertile durum 1E addition line, called DGE-1. Also by substituting 1E for the durum homoeologues 1A or 1B, we produced, two fertile disomic substitution lines, 1E(1A) and 1E(1B), which were designated as DGE-2 and DGE-3, respectively. The level of FHB resistance of the genetic stocks was studied in the greenhouse and in the field at Prosper, North Dakota. In the greenhouse, the 1E addition showed 32.15 % infection and was better than Langdon at 58.73 %, but not significantly different from 1E(1A) disomic substitution at 45.60 % infection. The 1E(1B) disomic substitution (88.29 % infection) had the highest FHB infection. Under natural conditions in the field, the observed infection rates were essentially similar. Among the three genetic stocks, the 1E addition DGE-1 had the lowest level of infection (at 10 %) followed by the substitution 1E(1A) at 20 %, and the substitution E(1B) at 70 %. The parental cultivar Langdon had 15 % FHB infection. The genetic stocks of durum may help produce several more alien addition and substitution lines involving different chromosomes and may help locate sources of FHB resistance.