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North Dakota scientist explores the treasures of wheat

2008-10-26 05:33:00
Author: Andrea Johnson

Today's technology is helping scientists find and build better wheat varieties faster.

Not too many years ago, new varieties were released about 10 years after a new line was first evaluated in greenhouses.

Now, scientists have ways to evaluate wheat lines quicker.

Shiaoman Chao, a molecular geneticist at the Agricultural Research Service (ARS) laboratory at North Dakota State University, studies the links between genetic traits and molecular markers that identify those traits.
 

A molecular marker is a kind of genetic tag that helps show a valuable trait in a specific wheat plant.

Molecular scientists like Chao receive tissue samples of plant leaves from wheat and barley breeders. She tests the samples to determine the genetic identity, or genotype, of each sample. Chao looks at molecular markers to determine if the plant carries the genes that the breeder is interested in, or not.

“By doing this marker testing in the lab, we can actually weed out a lot of plants the breeders don't have to deal with,” Chao said.

Plant breeders use that information to select which progeny should continue in variety development programs.

With help from lab instruments and computer software, Chao looks closely at genes to see whether she can find any differences in markers.

In many cases, the markers are no different between susceptible and resistant varieties.

“Developing a useful, robust marker is really the time consuming work,” said Chao. “A marker that sometimes applies to specific cultivars or specific lines may not be useful for other cultivars.”

Chao is studying genetic markers that indicate a wheat variety has resistance for wheat stem rust or Fusarium headblight (scab).

Work at the University of Minnesota and elsewhere is close to finding a gene that controls resistance to Fusarium headblight, she added.

“We have some markers that are coming from the gene itself,” she said.

Chao is also using the marker that indicates a wheat variety will likely offer high protein. The marker was developed by scientists at the University of California, Davis.

“The kernel will have a high grain protein content,” she said. “If you have that, you will improve the nutritional value. We're screening wheat lines to see if they carry those genes.”

The work of scientists, like Chao, can identify the best conventionally bred wheat lines. Their methods do not involved transgenic plants or GMOs. This allows U.S. wheat varieties easy access to countries around the world.

Public scientists and institutions conduct much of the nation's small grains breeding programs. The information they gain is generally available to anyone.

In addition to returning information to plant breeders, Chao has also designed and built a database on wheat molecular markers.

Plans are in place for Chao's work to be released on an Internet database site called GrainGenes. This site was developed by ARS scientists in the Genomics and Gene Discovery Research Unit, in Albany, Calif.

GrainGenes is found at http://wheat.pw.usda.gov.

Breeders will eventually be able to search the database for marker information to help them make wise decisions on which lines should be used for making crosses.

In the United States and abroad, plant breeders and others already use this site to obtain genetic information on wheat, barley and other small grains like rye, oats and triticale. Working together and studying each other's work limits replication and allows the process of finding the wheat genome to move ahead.

“What we try to do is help the breeders speed up the process of generating new varieties carrying the useful agronomic traits, so that the breeder can pass that on to the farmers,” Chao said.


Original article found at http://www.theprairiestar.com/articles/2008/10/24/ag_news/technology/tech1.txt

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