Research Progress on Woody Plants with Narrow Crown Phenotype

The narrow crown, a distinct form of canopy architecture and a specialized phenotypic expression of branch angle traits in woody plants, significantly influences key physiological processes such as photosynthesis, transpiration, and biomass accumulation. This phenotype holds substantial application value in forestry production. This article aims to elucidate the biological traits and formation mechanisms of the narrow-crown phenotype in woody plants by analyzing the contributions of plant hormones, their related genes, and specific key genes to the formation and determination of branch angles. Furthermore, the review explores applications of the narrow-crown phenotype in timber forestry, orchard production, breeding of new ornamental woody varieties, and forest tree genetic improvement. Finally, we summarize recent advances in research on narrow-crowned woody plants. On this basis, the future research directions of woody plants with narrow-crown phenotype were prospected, in order to provide reference for promoting the study of branching angle formation of woody plants and the production and application of woody plants with narrow-crown phenotype.