Genomic Study Shows Maize Adapted to Highlands 4,000 Years Ago

An international team led by researchers from Cornell University in New York and the Max Planck Institute for Developmental Biology in Tuebingen, Germany reveals that indigenous people in the American southwest started adapting maize to temperate growing seasons 4,000 years ago and refined it over in the next 2,000 years. In their paper published in Science, the group revealed the genetic changes that allowed the plant to live in harsher environments.

Maize, or corn, originated in Mexico and made its way to what is now the southwestern U.S. approximately 4,000 years ago, and quickly became one of the most important crops in the North America. The researchers note, though, that it did not make its way into the highlands for another 2,000 years. To better understand why the delay occurred, the researchers studied samples of 2,000-year-old fossilized maize cobs found in a cave back in the 1970s in Utah's highlands.

The team sequenced the genome of 15 of the cobs and compared the results to other maize lines. They report that the maize plants around the cave area were not as tall as other maize plants that grew at lower elevations, and that it had more branches, describing the plants as more bushy than other maize plants, a trait that allowed the plant to thrive in colder places. They also found evidence that the plant flowered earlier than most other maize plants, an attribute that would help it produce seeds before the earlier frost at higher elevations.

For more details, read the Research News at Max Planck Gesellschaft.