Geneticist’s corn research goes underground

A university researcher wants to build a better corn plant from the ground down. Shawn Kaeppler is using genetics to first analyze and then improve corn’s root system.

Kaeppler, a geneticist in the Department of Agronomy, looks at corn roots with the future in mind. He believes that farming systems in 15 to 20 years will use less fertilizer. Kaeppler wants to be ready with corn that will perform well in such low-input farming systems.

“Our goal is to identify traits that confer an advantage where phosphorus is scarce and incorporate those traits into lines that commercial breeders can use,” Kaeppler says.

Largely because of Wisconsin’s 1.3 million dairy cows, many farm fields today have more phosphorus than plants need. Even then, Kaeppler says, corn plants encounter brief periods when they can’t meet their phosphorus needs. This is especially true early in the growing season and sometimes later, when the crop is stressed.

Planting corn early usually pays dividends. “Growers who plant early tend to have higher yields come harvest,” Kaeppler says. “However, phosphorus is less available when soils are cold and young corn plants can face a temporary phosphorus shortage in early spring.”

The research may also be helpful in poor countries where the soils are frequently phosphorus-deficient. A large percentage of the world’s soils fall into the phosphorus-deficient category.

The traits Kaeppler is focusing on include the plant’s root architecture, how efficiently those roots take up low levels of phosphorus, and how efficiently the plants use the nutrient to produce a crop for growers.

Today’s Midwestern corn varieties were developed when fertilizer was readily available. “These varieties aren’t optimized for their ability to take up and use phosphorus,” Kaeppler says. So to find the traits he seeks, the geneticist is combining genes within cornbelt varieties, and expanding his search to older varieties and corn’s ancestral relatives.