Development Mechanism of Flower Type and Color in Tree Peony: A Review

Tree peony originated in China and is world-renowned for its colorful flower. The flower type and color is one of the important ornamental characteristics of tree peony, and it is also an important reference index for peony cultivars identification and new cultivars cultivation. To date, tree peony has been divided into 10 flower types and 9 flower colors. The application of molecular technology has made a prominent contribution to the study of the regulation mechanism of peony flower development. Many functional genes and transcription factors that regulate flower color and type have been identified and applied to the study of peony. In-depth understanding of the regulation mechanism of flower type and color contributes to improving the ornamental value and breeding of tree peony. However, there is no systematic description of the regulation mechanism of flower type and color in tree peony. This review systematically described the research progress on the regulation mechanism of peony flower color and type, to provide reference for the research and breeding of peony flower development.