δ2H of wheat and soil water in different growth stages and their application potentialities as fingerprints of geographical origin

- δ2H values of defatted wheat, soil water, rainwater and groundwater were determined.
- δ2H in wheat, soil water and rainwater changed consistently among different regions.
- δ2H in wheat was significantly correlated with the δ2H in soil water above 20 cm.
- Both wheat and soil water (0-20 cm) in the maturity might be used as fingerprints.

The study aims to investigate whether stable hydrogen isotopic ratio (δ2H) in wheat and soil water can be used as the fingerprint for geographical origin of wheat. Wheat was planted in three different regions in China across two years. The δ2H values were determined for soil water in three growth periods, and rainwater, groundwater, and defatted wheat in the maturity stage. The δ2H values both in soil water and defatted wheat showed significant differences among different regions and the changing trend of δ2H value in wheat was consistent with that in soil water and rainwater, but different from that in groundwater. The δ2H values in soil water in the depth of 0-20 cm in the maturity stage were positively correlated to the δ2H values of defatted wheat (y = 0.205x − 52.628, r2 = 0.645) and could be used as the potential indicator for tracing wheat geographical origin.