Lincoln, Nebraska, USA
August 21, 2014
Developing a wheat variety is an exercise in patience and diligence. No one knows this better than scientists at the Agricultural Research Service (ARS) housed in the University of Nebraska-Lincoln, where the new winter wheat “Mattern” debuted after twenty years of work. This wheat has been carefully inbred over generations to bring out desirable traits. “It’s like breeding horses,” says ARS research geneticist Bob Graybosch. “You cross one good wheat with another good wheat to create a better wheat.”
After generations of breeding, the final product, "Mattern," grows in a test field in Nebraska. The waxy winter wheat could offer unique textural qualities in foods. Photo courtesy of Bob Graybosch.
The reason this winter wheat is special has to do with starch, an essential and versatile part of the human diet. Beyond its basic nutritional use as the primary carbohydrate consumed by humans, starch has other textural qualities useful to the food industry. Wheat starches thicken, emulsify, and extend the shelf-life of many household food items including noodles, cakes, sauces, soups, and batters. “The food industry is huge,” says Graybosch, “Cereal chemists are always looking for new ways to experiment.”
Wheat starch is made up of two glucose polymers: amylose and amylopectin. Usually starch is 25-30% amylose and 70-75% amylopectin, but researchers were able to isolate a genetic mutation that yielded a wheat variety with higher amylopectin content. Amylopectin has attractive qualities like water retention, gelatinization, and stickiness. These are the kinds of attributes that interest food scientists.
When a wheat variety or cultivar is rich in amylopectin it is called “waxy.” “No wax is involved,” explains Graybosch. “When the first waxy corn varieties were introduced they had a candlewax appearance and the name stuck.”
The food industry gets most of its “waxy” amylopectin-rich starch from corn and rice, but Graybosch and other scientists at the ARS are hoping there’s room at the table for “waxy” wheat too. Only one other waxy wheat is currently grown in the United States, and it has been designed for the Pacific Northwest. Like any other crop, different types produce better in different parts of the country. As most of our nation’s wheat is grown in the Great Plains, it made sense to develop a waxy winter wheat compatible to the region.
Iodine staining indicates the amylose content of cut wheat kernels. "Mattern" kernels pictured above are bred to be amylose-free, giving this particular wheat a textural advantage over other varieties. Photo courtesy of Bob Graybosch.
“People think wheat is wheat, but there are thousands of varieties grown worldwide,” says Graybosch, “This particular variety took a long time to develop because it’s a winter wheat and requires vernalization.” Vernalization means that a plant needs chilly winter months to flower the following spring. Graybosch also had to “breed out” a poorly adapted variety from China which pushed back the wheat’s release another ten years.
“We developed this wheat because food industries asked for it,” says Graybosch. “There’s been a renewed interest in developing other starch sources. We used to source most of it from tapioca, but when World War II interrupted the trade of tapioca we had to switch to corn.”
Developing a new cultivar takes time and this variety was especially finicky as Graybosch and his colleagues were working with three naturally occurring mutations from poorly adapted wheat varieties. “It’s a continuous cycle of improvising and improving the cultivar” says Graybosch. Crop yields from field studies conducted from 2008 to 2012 show that this new variety either matches or surpasses other commercial winter wheats. A full description of “Mattern” was published in the Journal of Plant Registrations. UNL’s Nebraska Foundation Seed Division will produce and distribute seeds of "Mattern."
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