桔梗耐盐性考察及盐胁迫对桔梗幼苗总皂苷积累的研究

Objective: To explore salt tolerant ability of Platycodon grandiflorum seeds and seedlings, and the effects of salt stress mode. Methods: The seeds and the seedlings of Platycodon grandiflorum were treated with different concentrations of NaCl. Then, the growth traits index and physiologic index in the process of seed germination and seedling growth. The seedlings were treated with different salt concentration with foliar spray method and root irrigation method to study the effect on saponin accumulation of the seedlings. Results: With the increase of NaCl concentration, seed germination and the seedling growth were inhibited, the germination rate and relative germination rate were decreased; wilting phenomenon occur on the seedlings. The contents of proline, MDA showed increasing trends, and the activities of SOD, CAT and POD all presented a rising and then decreasing tendency. The method of foliar spray can effectively promote the accumulation of platycodins, compared with that of root irrigation. Conclusion: Platycodon grandiflorum's anti-salt performance is bad, and can be only suitable for low concentration of salt stress. The content of total saponins can be increased in the short time by leaf spraying method.