Durum Wheat as a Bridge Between Wild Emmer Wheat Genetic Resources and Bread Wheat

The primary stages of domestication and consequent polyploidization processes of bread wheat (Triticum aestivum, BBAADD) have diminished the genetic diversity within cultivated wheat germplasm. Wild emmer wheat (Triticum dicoccoides, BBAA), the progenitor of wheat, is a promising source for beneficial agronomical traits; however, introgression of such alleles into bread wheat was hampered by various factors, such as necrosis in F₁ pentaploid hybrids, failed seedling establishment, and frequent sterility. Therefore, we suggest to utilize durum wheat (Triticum durum, BBAA) as a bridge for transferring favorable alleles into bread wheat. We propose to screen wild emmer germplasm for valuable traits, cross promising accessions with durum varieties, confirm the phenotype in segregating populations, map the target gene(s)/quantitative trait loci (QTLs), and use marker-assisted selection for introgression into bread wheat. Here, we discuss the proposed concept and provide examples of successful transfer of traits such as drought resistance, high grain protein, resistance to stripe rust, powdery mildew, and fusarium head blight.