Q: Why are some corn kernels colored?
And why those particular colors? Jeannine, Albuquerque, New Mexico
Indian corn. Photo courtesy of CIMMYT, copyright, used with
A: Why are heads on top of necks? Why
are hearts connected to blood vessels? Why
are kernels colored? The answer is the
same: genes. Genes govern everything from the tiniest molecular interaction within a cell to the
shape of the whole body and also the color of corn.
Corn kernels have different colors because of genes that control color. Each kernel is an
individual with its own set of genes, like an embryo. Kernels are siblings housed on the same ear
and so naturally have many different colors. By naturally, I mean, through the course of natural
selection. One-color ears are unnatural products of human selection.
Livestock feeders prefer vitamin-rich yellow kernels, Southerners like white kernels, and Native
Americans favor blue. Years of deliberate selection, careful pollination, and storing of seeds
produced these single-color corn ears.
Saying an ear naturally has many colors does not completely answer your question: why
colors? On a deeper level: what does color do for corn?
In general, colors help a plant attract or repel other organisms or hide from predators. Colors
also occur as an integral part of biochemical reactions. For example, the chlorophyll in green
leaves reflects green light as it absorbs red and blue light from the Sun during photosynthesis.
Some studies suggest corn pigments promote resistance to insects or fungi that invade an ear of
By the way, corn has been around a long time. Primitive peoples of Central America or Mexico
were the horticultural geniuses who first cultivated corn at least 5,600 years ago.
Update (March 23, 2009) This just in from Science News:
Maize was domesticated from its wild ancestor more than 8700 years according to
biological evidence uncovered by researchers in the Mexicoís Central Balsas
River Valley. This is the earliest dated evidence -- by 1200 years -- for the
presence and use of domesticated maize.
Is Indian corn poisonous?
Sale of Indian Corn in 1846
(Answered June 1999, updated Aug. 1, 2007 and March 23, 2009)