Mapping Gene(s) for Grain Protein in Tetraploid Wheat (<i>Triticum turgidum</i> L.) Using a Population of Recombinant Inbred Chromosome Lines

Abstract

A ‘Langdon’ durum wheat line with a pair of 6B chromosomes from an accession of Triticum turgidum L. var. dicoccoides (Körn. in litt., in Schweinf.) Bowden [LDN(DIC‐6B)] previously was shown to have a gene(s) for high grain protein content (GPC). The objectives of this study were to develop a mapping population segregating only for genes on chromosome 6B, map the gene(s) for high GPC, and identify closely linked markers for use in marker‐assisted breeding for this trait. The 6B mapping population was grown in replicated field trials and evaluated for GPC. A restriction fragment length polymorphism (RFLP) map of this population was available. The quantitative trait locus (QTL) analyses provided strong evidence that a gene(s) for high GPC (named QGpc.ndsu‐6Bb ) is located near the centromere of 6B. The most likely location for the gene(s) is in the short arm between Xabg387‐6B and Xmwg79‐6B . The logarithm of the odds (LOD) score for this interval is 18.9. Segregation in this segment accounted for 66% of the variation in GPC. Eleven additional markers have been mapped within 7 centimorgans (cM) of the midpoint of Xabg387‐6B and Xmwg79‐6B . One or more of these markers should be useful in marker‐assisted breeding for high GPC in dorum wheat.