Fig. 4

Schematic depiction of the key developmental stages of flower bud and the analysis of floral organ identity and flowering-time related genes. a Flower developmental stages including floral transition, meristem specification, floral organ specification, floral bud dormancy and release, and blooming. Abbreviations for the flower bud developmental stages: undifferentiated flower bud stage (FBS1); flower primordium formation stage (FBS2); tepal primordium formation stage (FBS3); stamen primordium formation stage (FBS4); pistil primordium formation stage (FBS5); flower organ development and differentiation stage (FBS6); slow growth stage (FBS7); ovule appearance stage (FBS8); pollen formation stage (FBS9), blooming in winter. ap, shoot apex; fp, floral primordium; t, tepals; s, stamens; p, pistil; a, anther; o, ovule; po, pollen; es, embryonic sac. b The expression patterns of genes related to flowering time and floral organ identity at different flower developmental stages. c The phylogenetic tree of MADS-box genes and gene expression patterns of B-/C-function genes from various floral organs. The MADS-box proteins in wintersweet are marked by the yellow box