关键词: 刺桐, 磷酸二氢钾, 多效唑, 成花诱导, 生理效应

Abstract: To explore induction measures that promote flower bud differentiation in Erythrina variegata, this study investigated the effects of exogenous regulatory substances on the physiological characteristics associated with flowering in this species. Using E. variegata trees from urban green spaces as the research subjects, exogenous substances including potassium dihydrogen phosphate (KDP) and paclobutrazol (PAC) were applied via two methods: soil pit application and foliar spraying. The effects of different exogenous substances and application methods on the tree's nutritional components, hormone content, and flowering rate were analyzed, aiming to establish a regulation method using exogenous substances for inducing flowering in E. variegata. The results showed that the application of KDP and PAC significantly increased the contents of chlorophyll and carotenoids, as well as the soluble sugar content in leaves, while decreasing the soluble protein content, leading to an increased carbon-nitrogen ratio. The application of KDP and PAC significantly reduced the endogenous GA3 and IAA content in shoot apices but increased the ZR and ABA content, resulting in elevated ratios of ZR/IAA, ZR/GA3, ABA/IAA, and ABA/GA3. The application of KDP and PAC significantly improved the flowering rate of E. variegata branches, with the combined treatment of soil pit application and foliar spraying showing the most effective results. Therefore, the combined application of KDP and PAC via soil pit and foliar spraying is most conducive to the generation of leaf photosynthetic pigments, enhances photosynthetic products, increases the carbon-nitrogen ratio, regulates the balance of endogenous hormones, and ultimately promotes flowering in E. variegata.

Key words: Erythrina variegata, potassium dihydrogen phosphate, paclobutrazol, flower induction, physiological effects