Identification of Genomic Regions Determining the Grain Quality and Agronomic Characters in Durum Wheat

Dissection of quantitative trait loci controlling agriculturally important traits in durum wheat (Triticum turgidum L. subsp. durum) is required for molecular breeding to minimize inclusion of undesirable linked genes with the desired gene. The present study was conducted to identify genomic regions associated with grain quality and agronomically important traits. A doubled haploid population of 92 lines from a cross of ‘Strongfield’ and ‘Blackbird’ and the two parents were phenotyped at six environments for grain protein content, yellow pigment content, plant height, maturity, lodging, test weight, thousand-grain weight and grain yield. The parents and DH lines were fingerprinted with the Infinium 90K SNP assay. Composite interval mapping detected 24 QTL on 13 wheat chromosomes. Three grain protein content QTL were identified, one each on chromosomes 1A, 6A, 7A, and a QTL for pigment content was detected on 5A and on 7A. Nine QTL were associated with multiple traits. Two QTL were identified on 5A each associated with height, maturity, lodging, thousand-grain weight and grain yield. Three QTL were identified on 4B, each associated with maturity, lodging, test weight and thousand-grain weight. Two QTL on 4A were each associated with lodging, test weight, thousand-grain weight and grain yield, and two QTL on 7B each related to maturity, height, test weight and grain yield. A larger population will be required to discriminate between combinations of linked genes and pleiotropic effects. These QTL provide exciting opportunities to breed for genomic segments using SNP markers to assemble associated combinations of agronomic and quality traits.