• E-mail
• Print
• Comment
• Font Size
• Digg
• del.icio.us
• Discuss article

Scientists Locate Helpful Wheat Genes

Posted on: Friday, 2 April 2004, 06:00 CST

By JULIANA BARBASSA

FRESNO, Calif. (AP) -- Researchers have identified the genes that give wheat the ability to cross climates, a discovery that could aid humanity's ancient effort to make the world's most popular grain more productive, faster to mature and able to survive more extreme conditions.

A team of researchers at the University of California, Davis, has isolated and cloned the second of two genes that control vernalization - the plant's ability to flower only after exposure to a cold winter. That ability has allowed the plant to grow some in the fall but wait until after winter before flowering.

By finding the gene that activates the flowering and the gene that essentially puts a brake on the process, researchers developed a clearer picture of how wheat was able to cross from areas with long, cold winters to temperate regions, becoming the world's most important food grain.

"This will make us better breeders," said Jorge Dubcovsky, the head researcher and the university's wheat breeder. "We can now test if these mutations work better in different regions of the world."

This discovery also opened the door to manipulation of the process of vernalization, which could generate new, commercially significant varieties of wheat with shorter growing periods, earlier flowering or no flowering at all, said Dubcovsky.

People and wheat have moved together across the planet for the last 10,000 years, adapting to different climates and landscapes.

Human beings depend on wheat. It's the most widely cultivated grain, spanning more than 70 countries. Over 600 million pounds of the cereal - 23 percent of the food available for human consumption every year - are grown and consumed around the world.

In the same way, cultivated wheat needs humans. The cereal virtually lost its ability to propagate on its own many thousands of years ago, when it left its birthplace in the mountains of Turkey in the satchels of the world's first farmers. Early growers selected kernels that made harvesting easier by bunching tightly around the stalk, rather than those that fell to the ground when they ripened - the first step for the plant's natural reproduction.

The discovery at Davis, published in the March 12 issue of the journal Science, touched the core of this centuries-long relationship.

The same group of researchers who last year cloned the first wheat vernalization gene - VRN1, the gene that sets off the plant's flowering - this year identified VRN2, the gene that tells the plant to wait through weeks of cold weather before flowering.

A mutation in either one of these genes, the research team found, results in spring wheat varieties that don't need a cold winter to mature. Spring wheat, like the varieties grown in some really cold areas, can be planted after winter and will grow, flower and produce grain in the warm months.

Winter wheat retains the ancestral plant's ability to germinate and grow a little in the fall, then wait until winter passes to flower.

In the thousands of years since human beings developed a taste for bread, pasta, alcohol and other wheat-based goodies, different mutations led to types of wheat that don't need the cold to mature, Dubcovsky said.

"You can put in other genes, like a herbicide that will work only when the plant is not flowering," and a host of other possibilities, Dubcovsky said, explaining that these things are only being explored from a research perspective for now.

In California, 700,000 acres of wheat are planted every year from the mountains along the Oregon line to the hot, dry flatlands that join Mexico.

According to the National Association of Wheat Growers, the top producing states in 2002 were Kansas, North Dakota, Washington, Montana and Oklahoma.

California is not a big producer of wheat, ranking 14th to 17th depending on the year, but the cereal is an important part of crop rotation, helping prevent disease, returning nitrogen to the soil and breaking up the ground with its fibrous roots, said Bonnie Fernandez, executive director of the California Wheat Commission.

Craig Pedersen, a Lemoore, Calif., farmer with 2,000 acres of land on which he rotates wheat, corn and alfalfa, said farmers need the help of research like Dubcovsky's to stay afloat in a global marketplace.

"The U.S. is a high-cost producer," said Pedersen. "If we are going to remain competitive we are going to have to use every bit of technology available."

-----

On the Net:

University of California, Davis

More science, space, and technology from RedNova

Copyright © 2004 The Associated Press. All rights reserved. The information contained in the AP News report may not be published, broadcast, rewritten or redistributed without the prior written authority of The Associated Press.

More News in this Category