Combination of the 87Sr/86Sr ratio and light stable isotopic values (δ13C, δ15N and δD) for identifying the geographical origin of winter wheat in China

• All parameters in wheat were significantly different among different regions.
• 87Sr/86Sr in soil extracts was significantly different among different regions.
• Positive correlation of 87Sr/86Sr was observed between wheat and soil extracts.
• 98.1% of correct classification rate was obtained using these four indicators.

This study aims to investigate whether isotopic signatures can be used to develop reliable fingerprints for discriminating the geographical origin of Chinese winter wheat, and to evaluate the discrimination effects of δ13C, δ15N and δD, alone or with 87Sr/86Sr. In this study, the values of δ13C, δ15N and δD, and the 87Sr/86Sr ratios of wheat and provenance soils from three regions were determined. Significant differences were found in all parameters of wheat and 87Sr/86Sr in soil extract (reflecting the bioavailable fraction of soil) among different regions. A significantly positive correlation was observed between the 87Sr/86Sr ratios of wheat and soil extracts. An overall correct classification rate of 77.8% was obtained for discriminating wheat from three regions based on light stable isotopes (δ13C, δ15N, and δD). The correct classification rate of 98.1% could be obtained with the combination of the 87Sr/86Sr ratio and the light stable isotopic values.