Genetic Priorities

Friday, December 31, 2021

Cereal breeders in Ontario's academic and government institutions are building momentum.

By Jackie Clark

Corn and soybeans dominate the landscape in Ontario. However, producers also plant many acres of cereal crops. Winter wheat has grown in popularity in recent years, with 1,036,700 and 1,122,800 acres planted in 2020 and 2021 respectively, according to OMAFRA field crop data.

In addition to winter wheat, farmers in Ontario planted 96,800 acres of spring wheat, 168,700 acres of fall rye, 71,700 acres of oats and 51,500 acres of barley in 2021.

Many factors contribute to a cash cropper's decision to include cereals in their rotation.

"Market demand and prices, overall production conditions – season length primarily – but also soil type, crop rotation, workload management and soil health can all be factors a farmer takes into account when choosing to grow a small grain," says Willie Vanderpol, market developer for SeCan Association in southwestern Ontario.

Some growers are looking to harness ecological or soil health benefits by diversifying their rotation with a cereal crop.

Winter cereals can provide ground cover and prevent erosion with a fibrous root system, Vanderpol adds. Cereals like oats and rye may also be used as cover crops.

"Work at sites like the long-term rotation studies with the University of Guelph (UofG) at Elora and Ridgetown show improved resilience from adding winter wheat to a corn-soy rotation," she says. "Farmers will also use cereals as a non-host crop to break certain pathogen life cycles."

With so many reasons to include cereals in their fields, Ontario's crop producers need high-performing, resilient, locally adapted varieties. Breeders at the UofG and Agriculture and Agri-Food Canada (AAFC) are working hard to make that happen.

Breeding in Ontario

The province's cereal breeding is done through public institutions.

"My understanding is Dow Agrosciences was the last private company in the province to run a cereal breeding program," Vanderpol says. "Now cereal breeding done in the province is only by public programs at AAFC and the UofG. Winter wheat, spring barley, oat and spring wheat programs are run out of AAFC's Ottawa location, while both Guelph and Ridgetown campuses of the UofG house winter wheat breeding programs."

Her colleague, Phil Bailey, SeCan's eastern business manager, agrees.

"Most private companies have exited the eastern Canadian cereal breeding scene, and this makes it all the more important that AAFC/UofG continue to invest in the small grains breeding or else eastern growers will no longer have access to homegrown germplasm," he says.

Dr. Helen Booker is an associate professor in the department of plant agriculture at UofG. She took on the role of Grain Farmers of Ontario (GFO) professorship in Wheat Breeding and Genetics in 2020.

Booker collaborates with Dr. Lily Tamburic-Ilincic, who works as a research scientist at UofG Ridgetown, breeding winter wheat.

The role was established in 2014 and previously held by Dr. Ali Navabi, an accomplished breeder who tragically passed away after a battle with cancer in 2019.

Other breeders at UofG, including Dr. Peter Pauls, Dr. Elizabeth Lee, and Dr. Istvan Rajcan, stepped in to keep the wheat breeding program afloat until Booker was hired to step into her role, she tells Better Farming.

That effort "kept the momentum going," she explains. "Once you have a pipeline going you can produce something each year."

It takes about eight to 12 years from the breeder making the cross to establishing a genetically stable variety, and then testing for registration, she says.

So, "once a breeder leaves or retires or the program is halted for some reason, it's hard to start up that momentum again. If you stop making crosses there are holes in your pipeline, and you have to start over," she adds.

Dr. Gavin Humphreys, senior research scientist and winter wheat breeder for Eastern Canada with AAFC, also acknowledged this challenge.

In the early 2010s there was a reduction in breeding efforts in public institutions "because of a changing of the guard," he explains. Now, university and government programs are building up again.

"There is a limitation in terms of resources available but nevertheless, we do what we can with what we have," he says.

In Ottawa, Humphreys works alongside Dr. Andrew Burt, Dr. Raja Khanal, and Dr. Weikai Yan, who breed spring wheat, barley and oats, respectively.

Those researchers conduct the bulk of breeding for Ontario's cereals.

"Private companies do however, continue to screen material in Ontario to find adapted cultivars," Vanderpol adds. Those companies "instead source and screen material from various private breeding companies around the world."

Prioritizing traits

Farmers growing cereals are looking for high-yielding varieties with an appropriate maturity for their region, as well as some resistance to common biotic and abiotic stressors, Vanderpol says.

So, that's what breeders focus on.

"Farmers get paid for what they deliver to the elevator, so grain yield is always number one," Humphreys says. The variety "has to fit the maturity of the area."

Many producers "like their winter wheat to come off in July because then they've got time to deal with the crop before their corn and soybeans are ready to harvest," he adds.

Humphreys tries to remove varieties susceptible to common destructive cereal diseases like Fusarium head blight (FHB) and powdery mildew early in his breeding program.

"Anything that's really susceptible to FHB I discard," he explains.

He selects the highest yielding lines, "but I make sure that they don't fall down," he adds. "Sometimes the reason they're producing lots of grain is because they're really tall and have nice big heads, but then when the wind blows, they all fall, so that's no good."

Straw strength is a key trait, he adds.

Breeders conduct yield plot trials in a few locations, including Harrow, Ottawa and Charlottetown.

They "collect grain yield, maturity data, straw strength or lodging scores, plant height, test weight and 1,000 kernel weight," says Humphreys. Then may need to discard "the ones that are high-yielding but have other agronomic deficiencies."

After yield trials, breeders test for disease, and other stress resistance.

At UofG, breeders have "a really well-established protocol for a FHB nursery," Booker says. Varieties in that nursery are inoculated with FHB and raised under mist irrigation to test for resistance.

FHB is so significant in breeding in Ontario "because it impacts the crop but also because it impacts the grain," she explains. FHB can cause a buildup of mycotoxins in the grain, such as DON (deoxynivalenol) which make the grain unsafe for human or animal consumption.

"FHB is our number one disease to try to build resistance for," Humphreys agrees.

Some traits are more difficult to assess.

"Winter survival is harder to breed for because once every seven years you get a really bad year for winterkill," Booker explains. She's currently collaborating with Dr. Eric Lyons, director of the Turfgrass Institute and a professor in the department of plant agriculture at UofG, to understand some of the physiological limitations of cereals over winter.

Breeding for strong agronomic traits and resistance to stresses also contributes to the productivity of varieties that breeders select.

"Yield and yield stability are really impacted by winter survival and disease resistance," Booker says. "If you solve some of those production problems then yield and yield stability will follow suit."

Breeders also "work on powdery mildew resistance, which is particularly important on high-moisture years like 2021," Humphreys says. Races of powdery mildew change over time, so scientists must continuously select for resistance.

Pre-harvest sprouting resistance is also key in wet seasons, he adds. That trait is key in wheat and barley, particularly malting barley.

Barley yellow dwarf virus is another stressor present for all cereals, but particularly oats. It's important for barley not to be susceptible to net blotch.

Finally, quality testing is significant for cereals, because so much of the end-use is human food.

"Quality tends to be very specific to the end-use of the product," Humphreys explains.

Barley destined for malting is malt-tested in Winnipeg, Man., he says. High beta-glucan is desirable in oats because Health Canada acknowledges that it can reduce cholesterol. Oat breeders "don't like too much oil because it can cause rancidity."

Wheat quality factors depend on the type (hard, soft, red, white) which determines the types of food products that will be made from the grain. A cereal chemist with AAFC, Dr. Mehri Hadinezhad tests wheat bred in Ottawa.

Once varieties meet end-user criteria "then you can bring them forward for registration," Booker explains.

The Ontario Cereal Crops Committee (OCCC) can then support the variety for registration. The variety "goes through plant breeder's rights, we produce the breeder seed here, and that goes out to, in our case usually SeCan, and their seed growers begin to blow up the seed and then it goes to farmers," Booker explains.

After the eight to 12 years of development and testing, seed companies will do another four years of pedigreed seed production, Humphreys explains.

Challenges to success

In Ontario, there is "definitely much less investment in small cereals relative to corn and soybeans and much of the small cereals investment also happens more in the public research institution space," says Josh Cowan, the research and innovation manager for GFO.

Vanderpol agrees.

"I would say the combined budgets for public cereal breeding programs in Ontario are a drop in the bucket compared to the dollar amounts behind soybean and corn research," she says.

"The returns on cereal products pale in comparison to corn or soybean products. Cereals are grown on fewer acres overall and have a lower percentage use of Certified seed," she explains. "Until functional models are implemented, like Seeds Canada's Variety Use Agreement, variety developers won't be incentivized to develop varieties in, or test them for, the Ontario marketplace."

Government and university researchers are the ones shouldering cereal breeding for now.

"Even if an AAFC variety gets support for registration, if a seed company doesn't really like them, then they just become an also-ran variety that doesn't really go anywhere," Humphreys explains. "That's linked largely to this pedigreed seed production process. I had one this year that was not picked up by a seed company, so it's still sitting on the shelf waiting for someone to pick it up and run with it."

If seed companies feel a variety doesn't meet their needs or won't be competitive, they won't invest the labour and funds required to bring it to market for farmers.

Cereal breeders are also not able to use the same tools as corn or soybean breeders.

"I'm not allowed to work on or develop genetically modified wheat for anything but experimental purposes; it cannot be used in a breeding context," Humphreys explains.

"Because the consumer actually consumes a product of the seed, as opposed to a product like the oil, there's been a strong resistance to having any genetically modified traits put into cereals," he says. Breeders "had Roundup Ready wheat available, they tried to get it registered in the early 2000s."

However, "when we went for support for registration, it was voted down, and the main reason was the lack of consumer acceptance and lack of acceptance from Canadian export markets," he explains. Places like Japan and Europe wouldn't buy Canadian wheat if Canada couldn't guarantee it was genetically modified wheat-free.

"You can't put the wheat back in the bag, once genetically modified wheat is being grown on the Prairies," Humphreys adds.

Future directions

Despite challenges, there are exciting new directions and opportunities in cereal breeding.

"We have some tools that we didn't have 10 years ago in terms of the molecular markers for certain genes," explains Humphreys. "We also have some new breeding methodologies called genomic selection whereby you can select for minor genes and try to pyramid them all together using some high throughput genotyping methodologies."

The cereal breeders at AAFC recently applied for a grant to apply that new methodology to their program.

The methodology should help with "quantitatively inherited traits – traits that are controlled by many genes, each of which has a small effect," he says. "We can breed more readily for those traits by being able to find those genes using molecular markers, which you can't do if you don't have a genomic selection protocol as part of your arsenal."

Humphreys also hopes the cereal leaf beetle nursery, which is in its third year at the Harrow site, can expand.

"With climate change, the winters are less severe so there are diseases and insects overwintering in Ontario or arriving in Ontario earlier than they used to, so their potential for economic damage is greater," he explains.

Scientists are also working on developing double haploids using a process they got from the National Research Council in Saskatoon.

"Instead of two technicians producing 200 to 300 per year, we now have one technician who can product 500 or 600," Humphreys explains. "Not only does the process require less labour, which is the most expensive part of any breeding process, but it's more productive."

Booker is enthusiastic about the future of collaboration in cereal breeding.

"GFO and SeCan understand that for a crop like winter wheat it's important to have genetic diversity, so it's also important to have wheat breeding in Eastern Canada," she says. Those groups contribute to OCCC and are "a really good recommending committee."

In addition, by collaborating with AAFC in Ottawa on breeding and testing "you're getting out of just the university community," she says. The groups can exchange varieties to test at different locations and leverage the respective strength of each program.

Humphreys says that funders are looking for "better integration among programs.

"We're kind of competitors," he explains. However, "we've been encouraged to work more as a team going forward." BF