NEWS for North Dakotans
Agriculture Communication, North Dakota State University
7 Morrill Hall, Fargo, ND 58105-5665

June 17, 1999

Biotechnology Expanding Plant Breeders' Domain, Selection Efficiency

Greenhouses and field plots, the traditional domain of plant breeders, are not going to become relics because of biotechnology, say plant scientists at North Dakota State University. Instead, biotechnology is merely expanding plant breeders' scientific territory to include the laboratory and providing them new tools for completing their tasks more efficiently and quickly.

"It's always been a plant breeder's job to identify favorable genes and then manipulate them," says Richard Horsley, NDSU's six-rowed barley breeder. "Biotechnology just provides a new array of selection techniques."

In the case of barley, selecting lines with smooth awns (beards) can be done economically via a visual inspection of plants growing in a greenhouse, and a field trial is an effective method for measuring yield, Horsley says. But identifying other desirable traits using those conventional screening methods is less practical.

"Some diseases develop only in adult plants," Horsley says, "but growing out large numbers of adults in greenhouses simply is not feasible because the process requires too much space. By using various biotechnology techniques, we can extract pieces of plant DNA called molecular markers, which we use to identify genes that are associated with a specific trait such as disease resistance. All this work is done in a lab, so it's easy to see how biotechnology increases our efficiency. We don't need as much greenhouse space or as many nurseries."

That efficiency extends beyond space into time. The use of molecular (genetic) markers can cut the development period for a cereal cultivar by years, says Shahryar Kianian, whose job at NDSU is to identify beneficial wheat germplasm from outside the commercial and elite lines breeders use. The germplasm Kianian identifies can come from other lines that possess only one or two desirable characteristics, species related to wheat or unrelated plants.

"My job is to transfer desirable traits into material that the wheat breeders can use," Kianian says.

For example, Kianian currently is working with a low-amylose (starch) gene from a Chinese wheat line. This gene produces a waxy characteristic in wheat that is desirable for the production of Asian-style noodles.

The waxy trait for starch in wheat is inherited, explains Bill Berzonsky, NDSU's white and specialty wheat breeder. From his perspective, Berzonsky believes the initial benefits of biotechnology in plant breeding will come from identifying inherited genes that confer quality traits such as a special starch or higher protein content. The longer-term benefits will involve disease and herbicide resistance.

"Using molecular markers for making selections is not widely used in plant breeding yet, but this is changing rapidly," Berzonsky says. "It's never going to replace the field research we do because we'll still need to test varieties over different locations to ensure wide adaptation."

Another use of molecular markers is for the assessment of genetic diversity within breeding lines, adds Richard Novy, NDSU's potato breeder. He explains, "Potatoes are like people in that they don't tolerate much inbreeding. The intercrossing of genetically dissimilar parents can maximize genetic gains in potato."

Novy says breeders use molecular markers to assess how closely related breeding clones are to one another. Based on this information, breeders can then select parents for intercrossing that will produce progeny with improved hybrid vigor, and thereby increase the efficiency of a breeding program in its development of cultivars.

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Sources: Richard Horsley (701) 231-8142, Shahryar Kianian (701) 231-7574, Bill Berzonsky (701) 231-8156 and Richard Novy (701) 231-8536

Editor: Dean Hulse (701) 231-6136