Comparison of durum with ancient tetraploid wheats from an agronomical, chemical, nutritional, and genetic standpoints: a review

Under intense breeding, modern wheats, such as durum (Triticum turgidum L. ssp. durum), are believed to have lost nutritional quality and protein content while increasing productivity. Emmer (Triticum turgidum ssp. dicoccum Thell) and wild emmer (Triticum turgidum ssp. dicoccoides) are alternative resources for breeding programs by offering favorable alleles to be introgressed into modern materials and thus broadening their genetic diversity. Studies conducted so far have shown that durum wheat has better performance in agronomical qualities and protein quality than T. dicoccum and T. dicoccoides. However, its grain protein content (GPC) and Fe/Zn concentrations are lower. Several QTL for yield, GPC, and nutrient content in T. dicoccoides have been described, demonstrating its potential for transfer of important genes such as Gpc-B1 into modern cultivars. The Gpc-B1 gene increased the grain protein and Fe and Zn contents, but the agronomic performance of some of the modern recipients was reduced. Understanding the correlations and relationships between agronomic, chemical, and nutritional qualities would simplify selection through breeding for a single trait. Combining this knowledge with conventional breeding, MAS, and new breeding techniques would facilitate the QTL studies in these ancestral wheats and the development of new durum cultivars while retaining the agronomic qualities. In this review, we compare some grain parameters of T. durum, T. dicoccum, and T. dicoccoides wheats, including Fe and Zn content and their genetic aspects, and the existing information is analyzed and integrated for the future prospects of durum wheat improvement.