February 16, 2006

Genetics could pave way to better, more competitive U.S. wheat

Herbert Ohm
Purdue plant geneticist
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The goal is to combine desirable genes from different wheat types to produce plants more resistant to disease, drought and insects, while achieving higher yields and creating better quality products, said Herbert Ohm, a Purdue plant geneticist. A consortium of 18 institutions throughout the United States is involved in the project. Ohm is research coordinator for a district in the east region that includes Indiana, Illinois, Ohio, Missouri and Tennessee.

"Wheat is grown all over the country, but the types of wheat produced and the challenges farmers face with the crop depends on the climate and geography," Ohm said. "We will use genetics to identify genes that provide useful traits in wheat that will make it more competitive in the world market."

Several different types of wheat are grown in the United States, including spring and winter growth habit, white grain, red grain, bread or hard wheat, pastry or soft wheat, and durum or pasta wheat.

Many types of known diseases attack the plants depending on the region. Ohm's group will study several wheat pathogens, but will focus on glume blotch, which occurs almost annually throughout the eastern region. The fungus causes charcoal-colored lesions on wheat heads and leaves that result in grain loss.

Other diseases Ohm's group will look at are fusarium head blight, Hessian fly, barley yellow dwarf virus, leaf blotch and powdery mildew. Researchers also will consider the traits that affect soft wheat's milling, baking quality characteristics, such as softness and strength, as well as factors that cause soft textured grain.

People eat more wheat directly than any other grain, Ohm said. Improved wheat varieties could provide better bread, pastry and pasta by changing genes that impact cell wall strength, grain texture, color, and protein and starch content.

To pinpoint whether a wheat line possesses a desirable gene, the scientists will use bits of DNA known as markers. Then they can transfer the gene from a plant with the needed traits to another type of wheat and use the markers to determine if an improved plant has resulted.

"DNA markers provide efficiency in choosing genes and developing improved varieties of wheat," Ohm said. "This is a much faster and efficient way of selecting the best traits than just using field testing."

In addition to research aimed at developing better wheat, the scientists will hold workshops to teach farmers and students from kindergarten through graduate school about using genetic markers as breeding selection tools.

"We have the responsibility of education and also to provide breeders and producers with the markers so that they can use the technology to improve the country's wheat program," Ohm said.

The wheat varieties currently available to U.S. farmers were responsible for 78 percent of the country's domestic crop for 2001 to 2003. The average annual production is 38 million metric tons, worth more than $5 billion. However, U.S. wheat exports declined by almost 30 percent when 1980-1985 numbers are compared to 2000-2004 amounts. Experts say this is because many countries, including Australia, have more quickly adapted genetic tools for improving their wheat.

Writer: Susan A. Steeves, (765) 496-7481, ssteeves@purdue.edu

Source: Herbert Ohm, (765) 494-8072, hohm@purdue.edu

Ag Communications: (765) 494-2722;
Beth Forbes, forbes@purdue.edu
Agriculture News Page

A publication-quality photo is available at http://news.uns.purdue.edu/images/+2006/ohm-genemarker.jpg

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