University of Minnesota
Veteran corn breeder Ron Phillips and his colleagues bred this high-oil corn, here seen growing on the University of Minnesota’s St. Paul campus.
Photo: Patrick O’Leary
Researchers stalk a high-oil corn for fuel and food
By Deane Morrison
About five years ago, University of Minnesota adjunct professor Kim Joo heard from North Korean corn breeders about a variety with high oil content and asked if they would give her an ear. They did, and she brought it back for her colleague Ron Phillips to study.
An analysis showed its oil content reached a whopping 20 percent—way higher than the 3.5 percent of normal corn or the seven to eight percent of most “high-oil” corn on the market.
“That got my attention,” says Phillips, a Regents Professor of agronomy and plant genetics at the University.
Corn with high oil content holds potential as a source of raw material for biofuels, especially biodiesel. Also, says Phillips, it would make a high-energy animal feed. And, of course, the starch in its kernels could be used in ethanol production. Not to mention plain old corn oil for cooking.
Phillips and a team of University researchers found that besides being abundant, the oil in the North Korean corn contained lots of oleic acid, the major constituent of heart-healthy olive oil.
When the researchers grew the North Korean corn and crossed it with domestic corn lines, they created a variety with 12 percent oil content. That’s enough to produce up to 1,000 pounds of oil per acre, which is 70 percent more than from soybeans, according to University Extension economist Doug Tiffany, one of three other co-investigators on the team with Phillips.
“The biodiesel industry has struggled because of high soybean oil prices,” Tiffany says. “A good strategy is to use lower-cost fats and oils to make biodiesel.”
“The dream is to have high-oil, high-yield corn that can be used for biodiesel, ethanol, animal feed, and food.”
With the potential for producing more oil per acre, a high-oil corn could also move Minnesota closer to its goal of 20 percent biodiesel blends by 2015, says Phillips.
The researchers have identified genes responsible for the high oil content and are now working to breed a high-oil variety that’s also economically competitive. But there's the rub: Prices depend on yields, which are measured in terms of weight, and weight depends mostly on starch content.
“Usually, there’s a negative correlation between the amounts of oil and starch,” says Phillips. “Our goal is to break that relation.”
The 12 percent-oil corn had 10 percent less starch—which is to say, about a 10 percent lower yield. The researchers have identified regions of the corn genome that carry genes for both starch and oil production, and they hope to separate the genes for high oil and low starch and breed plants with high levels of both.
“We don’t know if we can do this,” Phillips cautions. “The dream is to have high-oil, high-yield corn that can be used for biodiesel, ethanol, animal feed, and food.”
The North Korean corn can’t be used “as is” because it is a hybrid and so does not breed true. American growers could produce the hybrid seed if they had the right parent varieties to cross. Unfortunately, says Phillips, North Korea has not been forthcoming about supplying pedigree information for the high-oil corn.
“I’m hoping someday North Korea will open up,” he adds.
The other co-investigators on the project are Roger Ruan, professor of bioproducts and biosystems engineering, and Nathan Springer, associate professor of plant biology.