New corn genetics are targeting cold tolerance and Goss’s wilt resistance at Carberry’s Canada-Manitoba Crop Diversification Centre.
The site’s field trials this year include three corn nurseries, part of a five-year hybridization program which involves the province, Agriculture and Agri-Food Canada, the Manitoba Corn Growers Association and the University of Manitoba.
“The fundamental thing is to establish a nursery, corn nursery, which really has those genotypes which are responsive to Manitoba environment(s),” Nasir Javed, University of Manitoba researcher, said.
The program ties into work from Lana Reid, Agriculture and Agri-Food Canada’s sole corn breeder. Genetic lines are developed by Reid before being evaluated in the field in locations like the one in Carberry. Those lines with desired traits are then moved through to the next stage of variety development.
“Most of our work for Manitoba is getting things at an early enough maturity and then Goss’s (wilt) would be the big disease,” Reid said. “We also work on other diseases. Not all of them are a big issue yet in Manitoba, although I expect with expanding corn acreage, they might be.”
Gibberella ear rot, which leads to toxic contamination of grain, is among those secondary diseases.
Another project hopes to cross early-maturing, but short, CanaMaize genetics with taller, late-maturing varieties.
The big chill
Last year, 15 genetic lines were put to the test after their parent lines showed promising germination at lower temperatures. Those lines were compared to five check plots of conventional corn varieties.
Javed’s team measured daily emergence percentage after seeding, weekly plant height and weekly leaf counts.
The trial found that early growth was not correlated to yield, although time to tasselling and silking was.
Two hybrids showed equal or better yields than the check plots.
“That is the first year’s finding, but this is the second year and we will continue testing newer and newer hybrids and probably (those) hybrids as well to see if the trend continues,” Javed said.
The Goss’s wilt nursery hopes to solve a growing problem in Manitoba. Since being identified in the province in 2009, Manitoba Agriculture crop pathologist Holly Derksen now says the disease has spread to all corn-growing areas in Manitoba.
The bacterial infection cannot be treated with fungicide, causes leaf discolouration and potential yield loss and spreads through corn’s ample and already difficult-to-manage residue.
Reid said she was excited to see the disease-screening nursery included this year. The Carberry nursery is the first public foray into Goss’s wilt resistance, although DuPont previously ran three years of screening with co-operation from Reid.
“We needed to expand the number of lines we could do, so one of the projects was to get an actual, public, nursery,” she said.
First-year results gave variable resistance to the disease, with some plants showing healthy new growth after exposure while others showed systematic infection.
“What we’re seeing is that those genotypes which had resistance to other diseases, say, leaf rust and the corn leaf blight resistance, we picked those and crossed them and tested them against Goss’s wilt and they are showing resistance to Goss’s wilt, so there are probably common gene families which are responding to these blights,” Javed said.
The Goss’s wilt nursery observed each line’s response to disease exposure but did not include molecular study.
Made for Manitoba
The two specialized nurseries echo Manitoba’s main breeding concerns, Lori-Ann Kaminski, research manager with the Manitoba Corn Growers Association, said. The association hopes to see corn spread west and north of its current growing areas.
Goss’s wilt, in particular, has been a largely Manitoba-specific concern.
“It has occurred in the States, but it hasn’t been an issue for Ontario growers yet, so that’s one of the reasons why it’s important to have it here,” Kaminski said. “On the cold-tolerance aspect of it, we know that all companies are working on lines and breeding for cold, but we also wonder about the interaction of cold tolerance and disease resistance.”
The Carberry trials have yielded several promising lines for future research and breeding, Reid said, although that does not mean that a new hybrid is around the corner.
The public corn breeder develops inbred and hybrid lines for particular traits, but those lines must then be incorporated by commercial companies.
“We can start to anticipate whether new stuff that Lana discovers will be important in those hybrids and companies are paying attention to the kinds of things that she’s developing as well as what they’re developing along the way,” Kaminski said.
Kaminski estimates it may take eight to 10 years to develop a commercial variety.
According to Reid, that number is closer to 10-15 years under conventional breeding, counting test time by companies before a variety is released, although that timeline is shortened considerably with new double haploid technology.
Most lines tested in Manitoba have been developed using the new technology, according to Reid.
“Any of the lines that are doing well will be further tested in a year or so,” she said. “It depends. There’s a mix of lines. Some of them are ready for release now. Some of them have a few more years before they’ll have enough data to release them.”
Most of the lines on display are also hybridized in yield trials across Manitoba, Reid added.
Both Reid and Kaminski say they hope both cold-tolerance and Goss’s wilt nurseries continue, although the project’s future has been thrown up in the air with the end of Growing Forward 2 funding.
Reid says she has applied to renew the corn nursery project through the next agriculture policy framework, Growing Forward 2’s successor.
“I have high hopes that it will be funded and Manitoba Corn (Growers Association) has high hopes that it will be funded and if it is, for sure, all of that work will continue for another five years, starting in March 2018,” she said.