Geographical origin verification of Crocus sativus L. grown using “two-segment” cultivation

Two-segment cultivation has recently been adopted to increase vegetative propagation and flower production of Crocus sativus in some Asian countries. Crocus sativus flowers (petals and stigmas) from Hangzhou (Jiande saffron with a geographical indication or GI status) and relocated daughter Crocus sativus corms from Shanghai (an origin without GI status) were investigated using stable isotopes (δ13C, δ15N, δ2H, δ18O) and elemental concentrations (%C and %N). Results showed that δ13C, δ15N, and δ18O of stigma and petal samples from daughter corms originating from Hangzhou and Shanghai had significant differences between the two regions (p < 0.001), even though the Shanghai origin daughter corms were harvested in Hangzhou. Furthermore, the δ15N values of stigmas and petals had a significant correlation (p<0.05, r = 0.566), but corresponding δ13C and δ2H values did not show a correlation (p>0.05). Finally, supervised PLS-DA pattern recognition models effectively discriminated stigmas and petals from crocus corms originating from the two locations. This research provides a globally-applicable mechanism to identify imposter GI Crocus sativus transferred from a non-GI origin before flowering and will enhance trust within the saffron industry.