Grain Protein Content QTLs Identified in a Durum × Wild Emmer Wheat Mapping Population Tested in Five Environments

Wild emmer wheat ( Triticum turgidum ssp. dicoccoides , WEW) was shown to exhibit high grain protein content (GPC) and therefore, possess a great potential for improvement of cultivated wheat nutritional value. A recombinant inbred line (RIL) population derived from a cross between T. durum var. Svevo and WEW acc. Y12-3 was used for construction of a high-density genetic map and genetic dissection of GPC. Genotyping of 208 F 6 RILs with 15K wheat SNP array yielded 4,166 polymorphic SNP markers, of which 1,510 were designated as skeleton markers. A total map length of 2,169 cM was obtained with an average distance of 1.5 cM between SNPs. A total of 12 GPC QTLs with LOD score range of 2.7-35.9, and PEV of 2.6-26.6% were identified under five environments. Major QTLs with favorable alleles from WEW were identified on chromosomes 4BS, 5AS, 6BS and 7BL. The QTL region on 6BS coincided with the physical position of the previously cloned QTL, Gpc-B1 . Comparisons of the physical intervals of the GPC QTLs described here with the results previously reported in other durum×WEW RIL population led to the identification of four common and two homoeologous QTLs. Exploration of the large genetic variation within WEW accessions is a precondition for discovery of exotic beneficial alleles, as we have demonstrated here, by the identification of seven novel GPC QTLs. Therefore, our research emphasizes the importance of GPC QTL dissection in diverse WEW accessions as a source of novel alleles for improvement of GPC in cultivated wheat. Key message Genetic dissection of GPC in tetraploid durum × WEW RIL population, based on high-density SNP genetic map, revealed 12 QTLs, with favorable WEW allele for 11 QTLs.