Low Phytate and Gpc-B1 Traits in Wheat: A Biofortification Winner Combo?.

Approximately 60% of the world's population are iron (Fe) deficient and over 30% are zinc (Zn) deficient. This situation is most acute in production areas with soils of low mineral phytoavailability, consumption of grain with low minerals concentrations and/or high concentrations of antinutrients such as phytic acid (IP₆). Gpc-B1, a gene introduced from T. turgidum var. dicoccoides, has been associated with 10 to 15% increased grain protein content (GPC) and Zn and Fe concentrations. A low phytic acid (LPA) mutant (35% less phytic acid) in wheat also increases bioavailability of Fe and Zn. This study aims to increase grain protein, Fe and Zn concentration and bioavailability by incorporating Gpc-B1 and LPA traits into elite Great Plains wheats, while maintaining yield. Two types of recombinant inbred lines (RILs) populations were created: 1) One population from Gpc-B1/LPA bi-parental crosses, and 2) Ten populations from Gpc-B1/LPA//adapted cultivars three-way crosses, in which F₁ derived from the initial Gpc-B1/LPA crosses were mated with Nebraska-adapted winter wheat materials. After F₄, all RILs were analyzed using the high inorganic phosphate (HIP) protocol and a molecular marker for Gpc-B1. Four genotypes LPA+GPC, LPA+WT, WT+GPC, or WT+WT were generated and yield trials using these genotypes were planted in two western and two eastern locations in Nebraska. Grain protein, Fe and Zn concentration will be analyzed during fall 2016. To understand the distorted segregation of the LPA trait shown in previous studies, three mapping populations have also been created. Genotyping by Sequencing (GBS) and linkage mapping analysis will be performed in these populations during fall 2016.  Observed segregation analysis of phenotypes using the HIP protocol suggests that the LPA trait is controlled by two or more genes. This study also confirms the results of a previous LPA segregation analysis using a different population and the polygenic inheritance of the wheat LPA mutation.