Genetics of biofortified wheat

Abstract

Biofortified wheat cultivars can be developed by reducing the levels of bioavailability inhibitors (such as phytate) and increasing the levels of bioavailability enhancers (such as fructans) in the grain. A double haploid (DH) population derived from a cross of MICH95.3.1.9 (a high grain phytate and high grain fructan genotype) and IDO637 (a low grain phytate and average grain fructan genotype) was evaluated for biofortification, agronomic and quality traits. Grain phytate concentration varied three-fold and grain fructan concentration varied two-fold. Significant differences were observed between genotypes for grain protein, Fe, Zn, Ca, Cu, K, Mg, Mn, Na, P and S concentrations, days to flowering, days to maturity and thousand-kernel weight (TKW). The DArTseqgenotyping platform was used to genotype the MICH95.3.1.9/IDO637 DH population. Forty-five quantitative trait loci (QTLs) for bioavailability, agronomic and quality traits were detected. Nine QTLs for grain phytate concentration and seven QTLs for grain fructan concentration were detected. Sixty QTLs for grain Fe, Zn, Ca, Cu, K, Mg, Mn, Na, P and S concentrations were detected. A multi-location trial and a multi-year trial were conducted to study the stability of biofortified wheat traits. Genotype, location, year and interaction effects significantly influenced the variation in all traits assessed. In both trials, genotype effects were the main source of variation forgrain phytate and fructan concentrations. A proof of concept broiler chicken feeding study was carried out over a 14-day period to demonstrate the efficacy of biofortified wheat in improving nutrient availability and production performance. Low grain phytate levels improved feed conversion ratio, tibia ash and phosphorus retention but did not affect feed intake or body weight gain. High grain fructan levels improved phosphorus retention but depressed feed intake and body weight gain.