Influence of Region, Harvest Year, and Variety on Stable Isotope Characterization of Xinjiang Rice From China

ABSTRACT Xinjiang rice exhibits exceptional nutritional quality, and makes an important contribution to Xinjiang's overall grain supply balance. Its stable isotopes are influenced by region, harvest year and variety which provide food safety and authenticity indicators. Nine rice varieties from northern and southern Xinjiang were collected over two harvest years (2018 and 2019) and were characterized using stable isotopes and compared with rice data from four other key rice regions in China. Overall, Xinjiang rice had more positive δ 13 C, δ 2 H and δ 18 O values than other rice regions. On a provincial scale, southern Xinjiang rice had more positive mean δ 13 C, δ 2 H and δ 18 O values (−26.2‰, −46.7‰, 25.4‰) than northern Xinjiang rice (−26.9‰, −54.8‰, 24.4‰) respectively, but mean δ 15 N values were more negative (4.3 and 5.7‰, respectively). Significant differences were seen for rice δ 2 H values between harvest years for both regions ( p < 0.001), with mean δ 2 H values of −57.0 and −44.5‰, respectively. Mean δ 2 H and δ 18 O values of “Hikaru‐mi‐1” rice was more positive, −34.9 and 31.0‰, respectively than other varieties. Multivariate analysis showed that there was a significant effect on the δ 13 C, δ 2 H and δ 18 O values of different rice varieties from two Xinjiang regions, which were related to varietal physiology, local climate, such as temperature, rainfall. This study characterizes influential factors affecting Xinjiang rice stable isotopes and provides the first data to support the construction of Xinjiang rice traceability database, as well as contributing toward improving China's large national rice origin database.