Seed World

Maize Roots Evolve to Be More Nitrogen-Efficient

Selective breeding of maize during the past century to create hybrids with desirable shoot characteristics and increased yield might have indirectly contributed to the evolution of root systems that are more efficient in acquiring nutrients such as nitrogen from the soil, according to researchers.
Their results suggest that future breeding efforts that directly select for positive root traits could lead to yield gains needed to help feed a growing world population, while reducing pollution from excess nitrogen and reducing farmers’ fertilizer costs.
About half of the yield gains in commercial corn hybrids in the past 100 years have come from improved plant genetics, says Larry York, recent doctoral graduate in ecology and now a postdoctoral research fellow at the University of Nottingham in the United Kingdom. The other half came largely from agronomic practices, such as fertilizer use and higher planting densities.
“A lot of research has focused on the shoots of maize plants, such as the direction of the leaves and how they capture light, or how the plants divide matter into ears and kernels,” York says. “We all know roots are responsible for the uptake of water and nutrients. However, relatively little is known about how roots do that.”
For more information, visit