Effect of different potassium ion concentrations on the accumulation of secondary metabolites in Lilium davidli var. unicolor bulbs

To investigate the effect of potassium application on the accumulation of active substances in lily of Lanzhou (Lilium davidii var.unicolor) bulbs, in this paper, potted lily of Lanzhou bulbs was grown in greenhouses, by fixing the amount of nitrogen and phosphorus fertilizers and growing lily seedlings with different amounts of potassium fertilizers, the content changes of total phenols, total flavonoids, total flavanols and polysaccharides in the bulb of Lanzhou lily at different growth periods when applied different mass concentration of K⁺ were determined by the forinol, aluminium chloride colorimetric, vanillin colorimetric and sulphuric acid-phenol methods. The test groups included blank group and test groups 1 to 3, corresponding to K⁺ mass concentrations of 0, 447.6, 671.4 and 895.2 mg/L. The results showed that: the overall trend showed an overall wavy variation in the active substance content of the bulbs. Compared with the blank group, the total phenolic, total flavonoid, total flavanol and polysaccharide contents in the Lanzhou lily bulbs of the test 3 groups were significantly increased by 16%, 35%, 219% and 69% (t=0.017, 0.032, 0.035, 92.111, P < 0.05). The results of the affiliation function analysis showed that the best results were obtained after the treatment of the three test groups. The findings can provide a theoretical basis for rational fertilization and quality cultivation of lily in Lanzhou.