New research tools, improved wheat quality, and better communication between buyers and breeders rank high among improvements wheat breeder Bob Zemetra has seen during 20 years of wheat breeding at the University of Idaho.

“When I started, we used anecdotal information from millers and bakers if our wheat wasn’t good,” Zemetra said. Vague comments didn’t help fix the problems.

“Now we meet annually with millers and bakers who test new material, and if it’s bad, they don’t mince words.” Those comments help Idaho wheat breeders produce varieties that best fit market demands and reap higher returns for growers. But even bigger breakthroughs are in labs and greenhouses.

Crossing two popular varieties
A new project in summer 2005 blended traditional wheat breeding methods and high technology in an experimental cross of two popular varieties. Also involved were scientists from Oregon State and Washington State Universities and the Agricultural Research Service.

Their cross of Brundage and Coda wheats yielded an impressive array of progeny, an estimated 20 to 30 with unique phenotypes or physical manifestations of different gene combinations. The array of types—tall ones, short ones, long heads, short heads, heads with awns or without—was striking visually.

Splitting the progeny of the two varieties into the multitude that grew in trials at the Parker Farm near Moscow and Kambitsch Farm near Genesee relied on selfing. Seeds from the cross were raised in the greenhouse to separate out traits, and to simplify the genetics by making each line homozygous—producing predictable offspring when bred with a genetically similar individual.

One seed was selected from each wheat plant for seven generations, allowing each of the new genetic lines from the cross to develop its own genetic identity.

Seeking cures, new no-till wheats
Zemetra had several objectives in mind when he chose Brundage, Idaho’s most popular soft white winter wheat, and Coda, a club wheat, valued for cake and pastry flour. He wanted to improve resistance to foot rot and explore new club wheat lines appealing to growers using no-till methods.

Foot rot can cause wheat stalks to lodge or fall before harvest. A fungal infection, foot rot typically strikes during extended wet spells.

Good fortune accompanied his choice of goals and Coda, the club wheat released by WSU in 1997. He found Coda is resistant to foot rot and also carries resistance genes for stripe rust—another major Pacific Northwest wheat disease—that differ from the stripe rust resistance genes in Brundage.
That diversity will help him accomplish another key goal, identifying molecular markers to allow rapid testing of whether genetic lines from the cross carry the resistance genes for foot rot and stripe rust.

Molecular biology, a powerful breeding tool, speeds research time
Before wheat breeders gained molecular biology as a tool, resistance testing relied exclusively on field trials, and the weather determined whether foot rot or stripe rust occurred.

New methods allow DNA extraction from hundreds of leaf pieces in a few hours rather than days. The DNA from leaves can identify plants carrying disease-resistance genes.

With assistance from Oregon State colleague Oscar Riera-Lizarazu, new molecular markers for foot rot resistance will soon be available for use.
The overall goal is to develop varieties that growers need to adapt to changing times. No-till producers want a shorter wheat leaving less straw after harvest.
“They not only want short, they also want a variety that matures early and has stripe rust resistance, high yield, excellent quality, and high test weight,” adds Zemetra. Somewhere in the family generated by the Brundage-Coda cross, that combination may be waiting.

Contact rzemetra@uidaho.edu