Identification of germplasm with enriched micronutrients of wild emmer and progeny of wild emmer × common wheat

Malnutrition caused by low concentrations or deficiencies of especially zinc (Zn) and iron (Fe) bio-micronutrients in human food affects a large proportion of the world population. Bio-fortification via conventional breeding or modern transgenic approaches improves bio-available essential mineral contents in edible portions of crops. This is regarded as an economically sustainable strategy for mitigating micronutrient malnutrition. Wheat (Triticum aestivum L.) is a vital cereal crop that accounts for ≈30% of total human cereal consumption in the world. Improving Zn, Fe and protein contents in wheat grain augments human nutrition, which especially alleviates micronutrient malnutrition in people who live on cereals. Wild emmer wheat (T. turgidum ssp. dicoccoides) is a critical potential donor of grain micronutrients, proteins and other desirable traits of common wheat. This study reported the screening of wild emmer accessions and their derivatives with common wheat for enriched grain Zn, Fe and protein concentrations. The study analyzed the relationships among grain Zn, Fe and protein concentrations, grain yield and yield traits, presenting a unique opportunity for wheat bio-fortification breeding. In this study, 32 accessions (derived from crossing wild emmer versus common wheat) and 4 lines of wild emmer were examined for grain Zn, Fe and protein contents. The progenies of wild emmer × common wheat exhibited not only high genetic diversity, but also enhanced grain Zn, Fe and protein contents. Principal component and correlation analyses showed that grain Zn, Fe and protein contents were positively correlated, suggesting that the three traits were combinable and could be simultaneously enhanced. Compared with common wheat alone, 3 lines of wild emmer wheat, and 14 wild emmer × common wheat accessions were identified as rich sources of grain Zn, Fe and protein. The results indicated that introgression of alien genes from wild emmer wheat to common wheat significantly improved grain Zn, Fe and protein contents in common wheat. Five accessions with improved micronutrient and protein contents, high grain yield and desirable agronomic traits were directly usable in wheat bio-fortification breeding.