Research Progress on Diversity and Variation in Flower Color

Abstract

Flower color is extremely diverse not only among flowering plants, but also in different populations and/or individuals of the same species (i.e. , flower color polymorphism). There is also color variation within the same or different floral structures. Understanding the formation and maintenance of the diversity of flower color provides a cue to unveil the evolution of flowers. A long standing view considers flower color functioning as visual signal for pollinators, which may facilitate pollen transfer and increase foraging efficiency. Here we introduce four aspects of flower color diversity at interspecific and intraspecific levels, four different methodologies of studying color variation, discuss three hypotheses that explain the color variation. Future studies combining phylogenetic analysis and involving multiple factors including pollinators, herbivores and environments will be much helpful for a better understanding the diversity and evolution of flower color.