Fig. 1

Observation of flower buds and plant phenotypes in Magnolia liliiflora ‘Hongyuanbao’. A The characteristic of twice flowering of ‘Hongyuanbao’. White bars, 2 mm; Red bars, 50 μm. B The time course of flower bud differentiation. Red bars, 50 μm. C The plant phenotypes changes of ‘Hongyuanbao’ during twice flowering process. S1, S2, S3 represent the early, middle, and later stage of the first flower bud differentiation, respectively. S4, S5, S6 represent the early, middle, and later stage of the second flower bud differentiation, respectively. The arrows pointed to the bud in April represent to the first flower bud differentiation process and the arrows in June represent to the second flower bud differentiation process