Abstract: In this paper, the ABCDE model of floral organ development was systematically introduced, and the molecular biology mechanism of different kinds of flowers in nature was explained. We plotted various patterns of flower development and deduced the function of each group genes and the phenotype of different types of mutants. It is helpful for understanding the secrets of the floral morphology.

Key words: flower structure, flower development, ABCDE model, quartet model, ectopic expression