Wheat Improvement: Change of Tech
by Laurie Gorton
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Why all the attention to wheat breeding, especially the biotech angles? In brief, after languishing for years, wheat improvement is now a hot field, pursued by life sciences companies and benefiting from advances in the technology of plant breeding.
Genetically modified (GM) wheat has yet to reach the market, but conventionally bred wheat will reap the first gains. Technologies introduced for GM crops have altered the playing field for wheat improvement. Genetic markers and similar modern techniques promise to revitalize older methods.
“All forms of breeding are human intervention in nature’s process,” said Craig Morris, PhD, director, US Department of Agriculture, Agricultural Research Service, Western Wheat Quality Lab, Pullman, WA, speaking to the 2011 Spring Technical Conference of AACC International’s Milling and Baking Division. Such intervention converted wild grass into domestic wheat more than 8,000 years ago. Today, biotech crops grow in 25 countries.
PRESSURE TO CHANGE.
This isn’t the first time at the dance for biotech wheat. Inspired by the success of its Roundup Ready soy and corn, Monsanto, St. Louis, MO, launched a similar GM project for wheat during the 1990s. But enthusiasm waned among end users for putting a bacterial trait based solely on herbicide tolerance into wheat, and the company abandoned the project in 2004.
Meanwhile, new technologies developed that favored intragenic gene transfer, a technique that picks up genetic material from within the species, rather than outside organisms. This change prompted new interest in the wheat germplasm stockpiles on which conventional breeders rely.
Also, wheat yield failed to keep up with other crops, and farmers converted to soy and corn for better economic returns. For example, corn increased in yield by 82% since 1992, but wheat’s yield rose only 7%. “For the first time in history, Canada now plants more canola than wheat and durum combined,” said William Wilson, PhD, university distinguished professor, Department of Agribusiness and Applied Economics, North Dakota State University, Fargo, ND. “The same [decrease in wheat acres] is going on around the world.”
Growers are putting on the pressure for GM wheat, according to Dr. Wilson. “They know GM increases productivity and lowers costs.” In April, the National Association of Wheat Growers held its fourth biennial Wheat Summit, which focused on progress in wheat biotech and crop improvement.
Unlike corn, soy, cotton and canola, where purely commercial breeders control crop development efforts, wheat breeding involves public-private relationships. “In the US and other countries, the vast majority of wheat germplasm is controlled by the public sector,” Dr. Wilson explained. In America, “public” means land-grant colleges, plus the one remaining US Department of Agriculture (USDA) wheat breeding site at Pullman, WA. These programs generally involve conventional breeding techniques, and the land-grant universities continue to dominate in this field.
The leading life sciences companies, however, are returning to wheat breeding, both conventional and bioengineered. “A lot of new people — smart people — are getting involved,” Dr. Morris observed, “and this will have a profound effect on wheat in the US.”
For example, Monsanto and Kansas State University formed a partnership in 2010 that will allow sharing wheat germplasm and technology. Later that year, Bayer CropScience, Monheim, Germany, signed a similar agreement with University of Nebraska-Lincoln.
“A key to the future will be public-private partnerships,” said Jim Peterson, PhD, vice-president, research, Limagrain Cereal Seeds, Fort Collins, CO. “It will get wheat competitive again, and it is an important part of what we are doing.”
FINDING THE BUCKS.
Such work requires funding. Historically, R&D investment in crops varied widely. Dr. Wilson reported average spending per acre per year of $10 for soy and corn but only 70¢ for wheat and 40¢ for wheat in Canada.
“We’ve seen the effects of the bad economy in huge cuts at major universities,” said Dr. Peterson. “This could really slow wheat development, if not for the new private investments.”
Some of that new money comes from USDA with renewal of its Triticeae Coordinated Agricultural Project (T-CAP) grant, a national effort that addresses improvement of barley and wheat. The program involves 56 researchers at 28 institutions in 21 states and spreads $25 million over a 5-year period, allocating one-third to education and two-thirds to research. Its general focus is yield and tolerance, with specific attention to traits related to climate change such as water use efficiency, nitrogen use efficiency, disease resistance, stability and low-temperature tolerance.
Public efforts also include overseas organizations, notably Australia’s Commonwealth Scientific and Industrial Research Organization (CSIRO) and CIMMYT, the International Maize and Wheat Improvement Center, a nonprofit headquartered in Mexico.
But by far, it’s the private sector that’s making most of the new research investments. “The past 18 months have seen a tremendous amount of new private dollars flowing into wheat development,” Dr. Peterson observed.
With revitalized interest in the economics of wheat, life sciences companies stepped up their involvement. Many jump-started their work by acquiring existing breeders and seed companies. In 2009, Monsanto leapt back in with its acquisition of WestBred, Bozeman, MT. Limagrain, based in France and the largest seed company in Europe, started actively acquiring breeders in North America. Other such companies with positions in wheat breeding include Arcadia Biosciences, BASF, Bayer CropScience, Dow AgroSciences, DuPont Pioneer and Syngenta.
“Before, it was one company pushing one trait,” Dr. Wilson said, “but today, it is six or eight companies with a lot of traits.”
The life sciences companies recognize that wheat is fundamentally different than soy or corn and not just in its hexaploid genetics. “When working with a bulk commodity crop such as soy, the focus will be on yield, although Monsanto also works on nutritionally enhanced soy, which involves quality aspects,” said Sean Gardner, business lead, sugarcane and wheat, Monsanto. “It is not the same for wheat, which already has many classes with specific functional and quality attributes.”
Mr. Gardner said that millers and bakers have questioned the basis for wheat improvement efforts. “I want to emphasize that function and quality are features of our plans,” he noted, “and we have been very explicit on this aspect during the past year. We collaborate and test on wheat with panels of millers and bakers.”
Initial projects at Monsanto will build on the legacy of WestBred’s programs. “Further along, we will look at other new technologies such as marker-assisted selection to screen for traits and quality at earlier points in the process,” Mr. Gardner said.
Arcadia Biosciences, Davis, CA, targets the agronomic and nutritional profiles of wheat, according to Roger Salameh, vice-president of business development. He identified qualities of interest to include resistant starch, high amylose content and high fiber.
Sustainability also figures into Arcadia’s plans in the form of a nitrogen-use-efficiency trait. “This is related to greenhouse gas generation,” Mr. Salameh explained, “because it addresses reducing emissions while increasing yields per unit of nitrogen applied.”
Nitrogen and water usage efficiency are both GM traits of interest, Dr. Peterson noted. “But Limagrain also does a lot with non-GM technologies, including breeding with doubled haploids and markers,” he added.
“GM trait development requires significant financial investment and time to satisfy regulatory requirements. Commercialization is still a number of years away in the US,” Dr. Peterson said. “We want to be ready when the time is right and consumer and industry attitudes are accepting.”
End users agree. “We have been talking to the life sciences companies,” said Hayden Wands, director of procurement for The Earthgrains Co., Downers Grove, IL. “And we say, ‘Give us a product with end benefits to the consumer such as higher folic acid, vitamin or mineral content.’ We’re asking this of the traditional breeders, too.
“The US should offer [wheat] quality you can’t buy elsewhere around the world,” Mr. Wands said.
UNDER THE HOOD.
Also making a big difference is all the new technology available. “The good news is that there is a huge potential for improving wheat by [non-GM] breeding techniques long before biotech comes along,” Mr. Gardner said.
For one thing, the cost of DNA analysis dropped significantly since 2008. Dr. Morris observed that 10 years ago, it cost 5¢ per DNA base; today it’s 5¢ per 215,000 bases. Marker-assisted selection (MAS) provides another important tool. A marker is a specific DNA sequence linked to a trait of interest. They act as flags locating a quality characteristic. “When you can identify such a bit of genetic material as a marker, you can take a leaf from any plant in the field and test it for that marker,” Mr. Gardner explained.
Better process control and computer-integration of methods now breathe new life into doubled haploid (DH) breeding of wheat, a 30-year-old technique. DH lines are made by pollinating wheat with corn, according to Forrest Chumley, president and CEO, Heartland Plant Innovations, Manhattan, KS. The resulting “wheat x corn” seed carries no corn chromosomes, but has a small wheat embryo that contains only half the usual number of chromosomes. After performing a chromosome-doubling step, plant breeders can create “pure lines” right away. This technique can cut the time required for developing a new wheat variety in half.
“DH is a conventional plant breeding method that takes years out of the breeding cycle: 11 months to produce a true-breeding line versus six years or more,” Mr. Chumley said. Heartland Plant Innovations is farmer-owned and dedicated to winter wheat, with spring and durum wheat DH lines available on request. “Monsanto recently opened a DH lab,” he observed. “Syngenta, too. Our operations are on a similar scale and are committed to supporting public sector breeders.”
By focusing on nondestructive analysis, mechanical techniques also have improved. Monsanto recently installed a chipper in its lab. It grinds a small chip off the seed. “We can test the dust from the chip and still keep the seed and plant it,” Mr. Gardner said. “You can run many markers on a small amount of dust. It is an incredibly powerful technology, a real step up that gets you to more elite material very quickly.”
Now, what about regulatory status? The US regulations governing testing and release of GM plants and animals don’t mention specific crops or breeds; they cover the general aspects. When a genetically modified organism (GMO) completes the regulatory process successfully, it is said to be “deregulated.” Confusing, but that’s the term used.
For all its promise, biotech wheat must get over additional hurdles after it clears regulatory approval.
First, will it be economically viable in the grain chain? From the seed companies’ point of view, whatever traits are selected, they have to be “big” enough to justify investing the $40 million to $100 million that it takes to get the seed into commercial markets.
Then there’s the problem posed by the practice of wheat farmers to hold back part of their harvest as seed for the next crop. Although wheat is self-pollinating, such on-farm practices cannot guarantee survival of the traits that will make biotech wheat feasible.
Potential difficulties involve the US wheat grading system, which does not have categories for such wheats. To maintain their economic value, these varieties must be segregated at farm and elevator to satisfy users of GM and non-GM wheat, with organic styles a particular concern. Millers may need to contract directly with growers to ensure identity preservation.
Testing for the presence of GMOs also presents challenges. According to Anne Bridges, PhD, chair, Approved Methods Technical Leadership, AACC International, and a Malvern, Australia-based specialist in cereal analytics, the biotech methods published in “AACC International Approved Methods of Analysis” were related to specific events such as the StarLink corn episode that occurred between 1997 and 2001.
Consumer issues run parallel. Studies by the International Food Information Council in 2002 and 2010 found very little consumer pushback on the subject of GM wheat. The future, however, may be different. The Wheat Industry Biotech Council formed in 2009 to foster communications, collaboration and an open dialog among industry organizations and companies working to commercialize biotech wheat.
Traits added to wheat “need to be relevant and understood by farmers, millers, bakers and consumers,” Mr. Salameh said.
For conventional breeding, it’s now. The Wheat Quality Council and its participating labs evaluate new wheat cultivars every year. The biotech timeline most experts quote involves 10 to 15 years from gene identification to field trials and commercialization. “But you don’t know when year No. 1 was,” Dr. Wilson cautioned.
International projects run ahead of US efforts. “There are field trials going on all over China as we speak,” said Dr. Bridges. She counted trials in Australia, Argentina and India.
Mr. Salameh confirmed her statement and added, “This puts pressure on the entire market.”
Wheat improvement is happening worldwide. “This is a great thing for the wheat sector,” Dr. Wilson said.
“We’re all in for exciting years to come,” Dr. Peterson observed. “It’s a race now.”