Abstract:

Background & Aim: Pollen grain is an important component for carrying and spreading plant genetic information. It contains the key code of angiosperm biodiversity, which can provide a micromorphological view for exploring “Darwin’s abominable mystery”. Pollen morphology is hereditary and highly diverse in angiosperms and has been used to study plant classification, evolution, ecology, biogeography and so on. However, current studies mainly focus on pollen shape, size, aperture, surface ornamentation, and microspore formation and development, and ignore pollen color. We intend to review the research on pollen color in angiosperms and suggest further studies.

Progress: Previous studies have outlined the chemical and genetic bases of pollen color, including biological factors (pollinator preference, visual crypsis, dimorphic selection, etc.) and abiotic factors (ultraviolet, temperature, humidity, latitude and longitude, etc.). Researchers have also introduced the practical applications for the understanding pollen color in apiology, plant tissue culture techniques, food science, horticulture and other related fields. We summarized the pollen color data reported in the last hundred years, which contains 47 families and 71 genera of angiosperms. We inferred the evolutionary patterns of pollen color using the Fitch parsimony method.

Prospects: In view of the recent advances in material science, spectroscopy, artificial intelligence (AI), evolutionary ecology and multiomics, we provide some thoughts and suggestions for future studies on the physical structure, systematic evolution and molecular mechanisms behind pollen color.

Key words: angiosperms, biodiversity, driving factors, material basis, measurement/quantization, pollen color