Analysis of the interactions between physiological substances and endogenous hormones in Bombax ceiba bud differentiation

2Plant bud differentiation is a process of transition from nutrient growth to reproductive growth, which is important for improving crop yield, breeding of good seeds and regulation of flowering time. To elucidate the morpho-physiological changes during bud differentiation in Bombax ceiba, this study was conducted in Haikou City, Hainan Province, employing paraffin sectioning, plant physiological assays, and LC-MS. We aimed to determine the dynamic changes occurring during this process. The results showed that 1) firstly, the transformation from growth point to flower bud is called floral primordial development, and secondly, the floral organ is mature.2) The content of soluble sugar and soluble starch of early-flowering and late-flowering Bombax ceiba first increased and then decreased, and the content of sucrose, soluble protein and malondialdehyde first decreased and then increased. The content of chlorophyll a gradually decreased and that of chlorophyll b and carotenoids gradually increased in early-flowering Bombax ceiba, while the opposite was true in late-flowering Bombax ceiba.3) 5Ds, CK and Auxin mainly acted in stage I and II, and ABA, SA, GA, ETH, and JA mainly acted in stage II and III.4) Soluble sugar and GA, soluble protein and IAA\CK, sucrose\malondialdehyde and IAA\CK\JA, soluble starch and IAA\CK\GA were significantly positively correlated, and chlorophyll and IAA\CK\SA were significantly negatively correlated, with the existence of synergistic and antagonistic effects co-regulating bud differentiation.This study provides a theoretical basis for exploring the mechanism of flower formation in Bombax ceiba and production practice. 3 Summary statementTo investigate the morphological and physiological characteristics of the bud differentiation process in Bombax ceiba, and to reveal the mechanisms of physiological substances and hormone interactions.