ABSTRACT
Objective:To investigate the effect of iron nanoparticles and melatonin on yield and quality of <italic>Fritillaria przewalskii</italic> and provide technical support for its domesticated cultivation. Method:Hundred grain weight was measured by conventional method；alkaloid content was detected according to protocols of the edition of 2020 <italic>Chinese Pharmacopoeia</italic>，chlorophyll，hydrogen peroxide，malondialdehyde，superoxide dismutase （SOD），peroxidase （POD） and catalase （CAT） were detected by spectrophotometric analysis，auxins，cytokinins，gibberellins，salicylic acid，jasmonic acid and abscisic acid were detected by ultra performance liquid chromatography tandem mass spectrometry analysis. Result:Zero-valent iron nanoparticles and melatonin significantly increased the hundred grain weight without affecting the quality. The effect of the two treatments on physiological and biochemical indexes in different stages were quite different，but the effects on content of endogenous hormones were basically the same. Correlation analysis showed that hundred grain weight was negatively correlated with malondialdehyde content，SOD activity and jasmonic acid content，but positively correlated with POD activity，salicylic acid content，gibberellins content，auxin content and abscisic acid content. The two treatments were separated effectively by principal component analysis，indicating that there were some differences in the mechanisms of growth promoting. The treatment of zero-valent iron nanoparticles mainly affected auxins，salicylic acid and abscisic acid. The treatment of melatonin mainly affected SOD，malondialdehyde and gibberellins. Conclusion:Zero-valent iron nanoparticles and melatonin can be used as a simple and practical technology to improve the stress resistance and yields of <italic>F. przewalskii</italic> in domesticated cultivation conditions.