Pollen Pigments

Abstract

The two initial characteristics by which pollen species are distinguished are shape and color. Many people presume all pollen is yellow. But, in fact, not only are some pollen non-yellow, but they may not even yield yellow pigment on extraction. Pollen which is yellow may not contain any carotenoids or carotenes although such constituents may have been present during microsporogenesis (Chapters 2 and 9). Many pollen do contain carotenoids, derivatives of tetraterpenes; these include carotene or the oxygenated derivatives, xanthophylls. Others derive their color from phenolic based flavonoids. Pollen often contains both pigments, but while extractable carotenes may be absent, flavonoid derivatives are always present. A comparison of relative amounts of the two pigment groups was made for Rosa damascena by Zolotovitch and Sečenska (1962). When all the yellow extracted pigment in 100 mg was calculated as carotene, they computed 0.203%, yet the actual carotene content in the pigment extract was only 0.058%, suggesting that about 75% of the pigment in this pollen was flavonoid in nature.