June 29, 2009
2009-06-29
Wheat concerns stem from fungus. Experts around the world are racing to create disease-resistant strains of plants.
More than the searing heat is making Brett Carver sweat big beads this summer. He’s worried about the Ug99 fungus, called stem rust. The Los Angeles Times described the fungus this month as a "time bomb” that could "wipe out more than 80 percent of the world’s wheat as it spreads from Africa.”
Carver, one of the sources for the Times’ story, is a wheat breeder at Oklahoma State University. He develops varieties of hard red winter wheat that are best suited for Oklahoma producers.
When I talked with Carver at OSU’s Stillwater Agronomy Research Stations, I asked if the 80 percent figure was accurate.
"That’s not overblown at all,” he said. "If you consider the resistance currently in varieties to the north of us, particularly the hard red spring wheat region, those varieties do not have much resistance at all to Ug99 or any strain related to it.
"We’re not that much better off here right now.”
But there is cause for hope, said Carver and Bob Hunger, an OSU Cooperative Extension wheat expert.
The call from Kenya The problem began 10 years ago when a type of stem rust fungus was discovered in Uganda that caused disease on wheat varieties that had been resistant to stem rust for many years. Ug99 spread to Kenya in 2001 and Yemen in 2007. It has been reported in Iran.The spread is alarming, but Oklahoma has some natural defenses.
Oklahoma winters are usually severe enough that stem rust cannot survive until spring.
Areas with milder winters, such as Texas, lack that protection.
Wheat breeders historically have selected wheat varieties that mature early, before the weather turns hot and dry, so Oklahoma wheat matures before spores are blown into the state. Breeders are racing to develop a wheat variety with Ug99-resistant genes before the fungus arrives here, Carver said.
OSU has a field of 50,000 wheat strains that are part of a 12-year development program.
From those 50,000 strains, 4,000 will be selected for additional study. Eventually, perhaps in four or five years, the number will be whittled to one.
That fungus-resistant variety will be released.
This effort to find solutions is worldwide. It’s not only an effort of the land-grant universities and the Agricultural Research Service, but many others including the International Maize and Wheat Improvement Center in Mexico and the Kenyan Agricultural Research Institute.
Carver has been sending varieties to Kenya to test resistance to Ug99 for four years.
About two years ago, Carver got a call from Kenya. A "line” of wheat he was about to abandon was suddenly showing promise.
"I was about ready to throw it away because it wasn’t highly resistant to leaf rust,” Carver said. "But now we have a super stem rust-resistant line, and it’s actually being grown at the Oklahoma Panhandle Research and Extension Center in Goodwell. We might lose some to leaf rust, but we can save a lot from stem rust. This line has resistance not only to Ug99, but also to a race related to it that could be even more damaging.”
NewsOK
Bryan Painter, Columnist
NewsOK.com
