Plant Genetics
New genes – showing resistance to the yield-robbing blackleg in canola crops – have been identified in trials.

New South Wales (Australia) Department of Primary Industries senior principal research scientist, Harsh Raman, said the study has unlocked the genetic make-up of canola to characterize major and minor genes resistant to the fungal pathogen Leptosphaeria maculans, which causes blackleg disease.

“Finding new sources of resistance, particularly resistance which is controlled by minor genes, is extremely important to the canola industry,” Dr Raman said. “Blackleg disease can cause up to 80 per cent yield loss in canola - in Australia, France and Canada resistance has been broken down in some canola varieties due to the emergence of new races of the blackleg pathogen.” | READ MORE
Published in Diseases
Soybean breeders continue to focus on early maturing soybean hybrids and bring myriad stacked traits to Western Canadian growers. Seed companies have supplied Top Crop Manager with the following information on the new soybean hybrids for 2017. Growers are advised to check local performance trials to help with their variety selections. Listing is by crop heat unit (CHU)/maturity rating.
Published in Soybeans
Kansas State University researchers recently announced a significant breakthrough in controlling the spread of the soybean cyst nematode, a parasitic roundworm that has caused anywhere from five to 100 per cent yield losses in Ontario.

Plant geneticist Harold Trick said the university has received a patent for the technology that “silences” specific genes in the nematode, causing it to die or, at the least, lose the ability to reproduce.

“We have created genetically engineered vectors [or DNA molecules], and put those into soybeans so that when the nematodes feed on the roots of the soybeans, they ingest these small molecules,” said Trick, who has worked closely with plant pathologist Tim Todd on this project.

So far, the scientists have found the technology has reduced the nematode population in greenhouse studies by as much as 85 percent. | READ MORE
Published in Diseases
Douglas Cook at New York University and colleagues from the University of Nebraska are using special microphones to listen to corn plants in order to determine what leads to wind-induced corn stalk failure. It turns out, the sounds stalks make just before failure are very similar to the sounds made when breaking. "We now think that plant growth involves millions of tiny breakage events, and that these breakage events trigger the plant to rush to 'repair' the broken regions. By continuously breaking and repairing, the plant is able to grow taller and taller," says Cook. It's an idea that mimics the science behind how human muslces are built: Muscles are strengthened when tiny microtears are repaired after lifting weights. Although most of the work is still in the early stages, this marriage of mechanical engineering and plant science and the information gathered so far can help plant breeders design optimal, strong plants. | READ MORE 
Published in Corn
A new breakthrough in soybean breeding could be a game-changer for the industry, and it comes at a time when soybeans are on Canadian producers’ minds more than ever before.
Published in Plant Breeding
"Ug99” might not mean much to the world outside agriculture, but few wheat diseases have so much potential to devastate production – and ultimately, consumer access to a basic staple – around the world.
Published in Diseases
The warning bells rang loud and clear in 2013 when a shift in clubroot pathotypes overcame clubroot-resistant canola varieties on the market. Tests found the pathotypes present were capable of overcoming most of the clubroot-resistant canola hybrids. Because this breakdown in resistance wasn’t unexpected, plant breeders have continued to look for alternate sources of resistance that can be bred into new varieties to help manage the multiple pathotypes that have been identified in Alberta.
Published in Diseases
Fushan Liu never expected the sight that greeted him last year in his lab at the University of Guelph: arabidopsis plants grown two and a half times their normal size.

As a postdoc at the University of Guelph’s College of Biological Science, Liu had been working on a project transforming starch branching enzymes (SBEs) from maize into arabidopsis plants. For weeks, he’d been analyzing the interesting effects of the maize SBEs on the arabidopsis plants’ starch pathways. Then one day he realized the plants he’d been working on had grown much larger than the control plants. Not only that, but there were also far more seedpods, and their leaf and root systems were bigger, too.

“That was the beginning – I saw a really big arabidopsis plant and thought, let’s take a picture. Something has happened biologically,” Liu says.

He showed the photo to his supervisors, Guelph professors Michael Emes and Ian Tetlow. 

“We’d found some interesting effects on the starch, and had done all sorts of measurements,” Emes echoes. “And then one day we stood back and looked at the plants, and we finally saw the wood for the trees. We saw these plants were really different.”

A healthy plant from a typical arabidopsis line normally bears about 11,000 seeds; the new plants bore 50,000 seeds per plant – a more than 400-per-cent increase in seed production. 

“The plants were bigger, the leaves were bigger, there were more stems, there was more flowering and more seed,” Emes says. “It’s not just that there were a lot more seeds, there was a lot more of everything. 

“It was one of those serendipitous events in science. If you’d asked me to produce a plant with more seeds I would have said you couldn’t get there from here,” he adds.

Liu’s focus had been on trying to analyze how the SBEs’ functions changed in arabidopsis leaves, but after this discovery his focus changed to studying the impact on seed yield and biomass, comparing transformed plants with wild-type arabidopsis plants. Importantly, the quality of the oil remained the same as for the non-transgenic plants.

The team published their findings this spring in the Arabidopsis is not a starch crop, but an oilseed genetically similar to canola, so the obvious application of the finding is in breeding higher-yielding oilseed crops for biofuels. Emes and Tetlow have already begun preliminary work with canola, but also foresee potential applications in camelina, soybeans and other crops.

While the dramatic increase in seed production might not occur as easily in canola as in arabidopsis, Liu says even a tenth of the effect would still mean an increase of 40 per cent – a substantial impact on yield.

“This is orders of magnitude different than conventional breeding,” Emes says.

But what, exactly, is going on in the plants?

The good times are here
Emes has a theory that the starch metabolism in the transformants has improved the plants’ ability to grow and reproduce. 

The team is working on two lines using two starch genes from maize. In one of the new lines, there is a massive increase of starch in the leaves, which the plant breaks down overnight. In the other line, there is a bigger impact on yield; there is still an increase in starch in the leaves, but it doesn’t all break down at night, leaving a carbohydrate reserve.

“We know that carbohydrates, during seed development, come from the leaf through the vascular system and into the reproductive system. These are important to flower development and what’s called embryo abortion – the plant makes a kind of ‘decision’ on whether or not to produce seeds,” Emes explains. “Flower and seed production is limited by the supply of carbohydrates. So these plants are now saying, ‘The good times are here, let’s go for it.’ ”

Emes suspects that the wild type arabidopsis plant has an endogenous mechanism that constrains growth because it’s genetically evolved to always keep something in reserve. But in the transgenic plants, the brakes have been taken off. 

If the scientists can crack the code on the maize SBEs’ effect on oilseeds, Emes sees potential applications for feedstock and oil for human consumption, as well as biofuels. He is currently seeking public and private funding to continue the project in canola.

Liu, now a regulatory scientist for the J.R. Simplot Company, says much more work is required to improve seed quality as well as yield in future breeding projects. “If you want to improve quality, if you want to improve omega-3 fatty acid or other special fatty acid content, for now I don’t have any insight on how you can improve those things, from this study,” he says. “At least, from the analysis of the arabidopsis you don’t see a change in these properties – you just get higher yields.”

But Liu is optimistic about the future applications of his work. “Genes are so powerful,” he says. “One small change could be a potential opportunity for dramatically improving crops.”
Published in Plant Breeding
Bt corn has been on the market in Canada for over a decade; last year, Bt corn hybrids were planted on 3.1 million acres across the country. 

The technology is incredibly, and increasingly, valuable to Eastern Canadian growers, where 2,035,000 of the total 2,295,000 acres of corn were planted to Bt hybrids in 2015. But the ever-present risk of the development of insect resistance to the technology is keeping the industry on its toes.

While resistance hasn’t yet developed in European corn borer (ECB) populations in North America, reduced susceptibility has been noted in some populations of corn rootworm, according to Jocelyn Smith, a research associate in field crop pest management at the University of Guelph’s Ridgetown Campus.

But resistance can be delayed with proper management. In Canada, stewardship of Bt technology takes the form of insect resistance management (IRM) plans, which chiefly involve maintaining refuges to delay the development of resistant insect populations. 

Stewardship also entails rotation of traits in the field, as well as the use of stacked traits.

“The most important thing we can do with this issue is educate growers more about the risks they’re taking if they continuously use traits for rootworm,” Smith says. “Their sheer numbers and biology give them advantage.”

This is a message familiar to Eastern Canadian corn producers, and they’ve taken it to heart. The Canadian Corn Pest Coalition (CCPC) – made up of academics (such as University of Guelph researchers), the Canadian Food Inspection Agency (CFIA), the provincial ministries of agriculture, and industry representatives – has been conducting surveys on insect resistance management compliance since the late 1990s. 

Until 2012, those surveys were conducted in alternating years with CFIA IRM compliance surveys, but that year, stewardship compliance rates were so high CFIA discontinued them unless “in future, industry practice shifts from using blended refuge.”

But the CCPC’s bi-annual survey continues. “The increase in compliance with refuge area requirements from 2013 to 2015 occurred in all three provinces and now stands at 91 per cent in Ontario, 90 per cent in Quebec and 91 per cent in Manitoba,” the 2015 report concluded.

According to the same report, compliance tended to be higher in the 35 to 44 age category, but lower among producers who believed stewardship requirements to be “only somewhat important.” In addition, the report indicates awareness of stewardship requirements has declined since 2013, particularly in Ontario; compliance was also lower among those who believed they did not understand requirements.

More education needed
Cindy Pearson, national manager of the CFIA’s Plant Biosafety Office, says the onus is on companies marketing Bt products to educate producers regarding the need for delaying resistance and how refuges work.

“IRM plans are the responsibility of the company to whom the Bt corn product has been authorized, and CFIA receives specific reports from companies that
detail their various activities on that front,” Pearson says.

The survey notes refuge-in-a-bag (RIB) hybrids, which contain the required percentage of refuge seed, resulted in significantly higher compliance rates after their market introduction several years ago. The market has also changed with the introduction of stacked hybrids with multiple Bt traits or modes of action against the insect pests.

“There are currently three traits available for corn rootworm control,” she says. “Where we have growers with long-term use of two of those traits on their own (not in a stacked product), we’ve started to
notice some shifts in susceptibility when we test those populations in the lab.”

This doesn’t necessarily mean producers can see resistance developing in the field, but it’s still a red flag.

“We need to focus on informing continuous corn growers that the three-year limit is important,” Smith says. “We may have had a situation where a grower has used a single trait for years and it’s compromised, so then when they use the stack there’s only one viable trait remaining against the pest.”

Smith also emphasizes monitoring as a key aspect of stewardship. “If you are growing corn on corn, scout your corn late in the season and if there’s less than one beetle per plant you might be able to get away without using transgenics,” she says. “You might be able to hold off on using some of the technology in the following year.”

Smith also recommends rotating management options — in other words, soil insecticides and Bt traits.

“And again in season, keep an eye on the pest situation in the crop. For ECB and rootworm, you need to monitor whether they are being controlled by the Bt hybrids or not. If they are not, you need to notify the CCPC and the trait provider,” she says.

As long as they use Bt technology, producers are on notice to use it well. Resistance is in nobody’s interest except the insects.
Published in Corn
Breeders are once again introducing new canola varieties, releasing commercial quantities for the 2017 growing season. The respective seed companies have provided the following material to Top Crop Manager for informational purposes. Growers are encouraged to consult third-party trials, such as the Canola Council of Canada’s Canola Performance Trials, for further information, and talk to local seed suppliers to find out how new varieties performed in local trials.
Published in Canola
A new, high-yield alfalfa variety developed in the Maritimes will go to market in February when Agriculture Agri-Food Canada puts the results of 28 years of research to tender. CBC News reports. | READ MORE
Published in Genetics/Traits
Spraying barley crops with RNA molecules that inhibit fungus growth could help protect the plants against disease, according to a new study published in PLOS Pathogens.
Published in Diseases
Researchers at Rice University in Houston are leading an effort to build tools that can detect, quantify and track the dispersal of genetically modified crops and animals, as well as their byproducts, in the environment.
Published in Genetics/Traits
Allen Good believes there’s a difference between the “gold standard” of field trials and the ways some producers run their operations.
Published in Genetics/Traits
In Saskatchewan, leaf blotch disease complex has become more prevalent in oat fields in recent years, but very little is known about the impact of these diseases on oat production. In infected fields, oat yield and grain quality, including test weights, are often reduced, which can impact milling quality and reduce returns.
Published in Diseases
Public and private plant breeders continue to bring new cereal varieties to market, with improved yield, disease resistance, and agronomic performance. Available in commercial quantities for the 2017 planting season, these new varieties continue to push yield boundaries.
Published in Cereals
Gene editing, a type of genetic engineering in which DNA is added, “deleted,” or replaced in a target genome, is revolutionizing plant breeding across the world. In 2015, the CRISPR-Cas9 gene editing system was called “breakthrough of the year” by Science magazine. This spring, all of Canada’s prestigious Gairdner International Awards went to five scientists involved in developing CRISPR-Cas9 as a genome editing system for eukaryotic cells.
Published in Plant Breeding
An international research team has identified two genes which could help protect barley against powdery mildew attack.

Led by the University of Adelaide in Australia and the Leibniz-Institute of Plant Genetics and Crop Plant Research (IPK) in Germany, the research will give plant-breeders new targets for developing lines of barley with resistance to powdery mildew.

The two genes, HvGsl6 and HvCslD2, were shown to be associated with accumulation of callose and cellulose respectively. These two polysaccharides play an important role in blocking the penetration of the plant cell wall by the powdery mildew fungus.

Published in two separate papers in the journal New Phytologist, the researchers showed that by "silencing" these genes, there was lower accumulation of callose and cellulose in the plant cell walls, and higher susceptibility of barley plants to the fungus. Conversely, over-expressing HvCslD2 enhanced the resistance in barley.

"Powdery mildew is a significant disease of barley wherever it is grown around the world, and resistance to the fungicide most commonly used to control it has been recently observed," said Alan Little, a senior research scientist at the University of Adelaide, with the ARC Centre of Excellence in Plant Cell Walls in the School of Agriculture, Food and Wine, in a press release.

"If we can develop barley with improved resistance to powdery mildew, it will help barley producers increase yields and maintain high quality."

In the plant and pathogen co-evolutionary battleground, host plants have evolved a wide range of defence strategies against attacking pathogens.

One of the earliest observed defence responses is the formation of cell-wall thickenings called papillae at the site of fungal infection. They physically block the fungus from penetrating the plant cells.

In barley, the papillae contain callose and cellulose as well as other polysaccharides, but the genes involved in accumulation of these carbohydrates in the cell wall have not been identified.

"Our results show that these novel genes are interesting targets for improving cell-wall penetration resistance in barley and maybe other cereals against fungal intruders," said Patrick Schweizer, head of the Pathogen-Stress Genomics Laboratory at IPK.

"Now we can use these genes to identify molecular markers for breeding enhanced resistance into modern barley."

The two papers can be read online here and here
Published in Genetics/Traits
According to new research from University of Virginia economist Federico Ciliberto, widespread adoption of genetically modified crops has decreased the use of insecticides, but increased the use of weed-killing herbicides as weeds become more resistant.
Published in Genetics/Traits
Eastern Canada is Canada’s biggest winter wheat producer, with more than one million acres seeded for harvest in 2016, compared to Western Canada, which clocks in at about 600,000 acres. But winter cereal varieties have typically been bred for Western Canadian conditions – at least, until now.

Two research and breeding projects are underway looking at cold tolerance and winter hardiness in winter cereals in an Eastern Canadian context.

“Cold tolerance, winter survival and winter hardiness in Eastern Canada is a complex beast,” says Jamie Larsen, a research scientist in perennial cereals, fall rye and winter triticale breeding for Agriculture and Agri-Food Canada (AAFC).

Larsen is based in Lethbridge, Alta., but his research has an eastern angle. Five years ago, he was hired out of the University of Guelph to be AAFC’s perennial cereals breeder in Lethbridge. One of the focuses of his program is to develop a winter cereals breeding project – fall rye, winter triticale for Canada and durum wheat. Collaborations in Ontario have led to the testing of winter triticale varieties for three years, and plots in Harrow and Palmerston are testing out winter triticale varieties under Ontario conditions.

He says the differences between Western Canada and Eastern Canada are significant when it comes to winter hardiness. Where cereals are generally bred to be tolerant to long periods of freezing in Western Canada, Eastern Canadian varieties need to be both cold tolerant and tolerant to ice encasement, freeze-thaw cycles and frost heaving.

“In Western Canada we don’t get as much snow and icing-over, thaws and water settling followed by freezing. In Ontario it comes and goes, so you get this puddling in the fields and it gets cold again and freezes,” he says.

Once the three-year project’s funding runs out, Larsen and his team hope to extend it to keep the study going. “From an Ontario perspective, there are concerns around eutrophication of the Great Lakes, and one way to deal with that is to plant more winter crops that can survive the winter, and to make use of those nutrients and limit run-off,” he says.

But the results from the triticale study are also extremely promising from a grain yield and biomass perspective. “The yields are incredibly high, much higher than winter wheat in Western Canada,” he says. “What we saw is a yield advantage as high as 50 per cent in the winter triticale over winter wheat. In some cases the only thing that could beat them is the hybrid rye that’s now out in the marketplace. We will find out shortly if the same holds true in Ontario.”

Larsen is especially optimistic about triticale’s potential as a biomass crop. “In the U.S., it’s used by dairies and livestock producers as a double crop in significant acreage and this practice, currently at approximately 1.2 million acres, is growing,” he says.

“Canadian varieties are not cold tolerant enough, but if we can select for varieties that work in Ontario there could be pretty quick uptake for this material, and I think we’re close.”

Response genes
At the University of Guelph, wheat breeder and associate professor Alireza Navabi, while breeding for winter-hardiness in wheat for Eastern Canada, is also working on two different characteristics of wheat that are important to cold tolerance – response to vernalization, and response to photoperiod, or day length.

Flowering and maturity of wheat are controlled by interactions between vernalization and photoperiod response genes in addition to earliness genes, Navabi explains. “Vernalization can work as a survival mechanism,” he says. “Wheat makes the transition from a vegetative to a reproductive stage after it’s been exposed to cold temperatures. After the winter, when the vernalization requirement is met, winter wheat is ready to flower.”

Wheat responds differently to different photoperiods. Some varieties are sensitive to photoperiod while others are not.

Photoperiod insensitivity can be beneficial in breeding winter wheat varieties that are better adapted to northern contexts. In combination, vernalization and photoperiod response genes determine how quickly a particular genotype will make the transition to a reproductive state and therefore how they might adapt to a particular environment.

Navabi’s graduate student, Alex Whittal, has characterized a “very wide set of winter and spring wheat genotypes” in wheat for genes that control response to photoperiod and vernalization response genes.

“There are different genes controlling these two mechanisms,” Navabi says. “We now know exactly which alleles are present in each genotype tested, and based on which allele each genotype has, we can predict their response to vernalization if they are sensitive or insensitive to photoperiod. We also know that there is a frost tolerance gene in close association with vernalization genes.”

Currently, Navabi and Whittal are operating on an Ontario Ministry of Agriculture, Food and Rural Affairs-University of Guelph partnership project in collaboration with AAFC’s winter wheat breeder in Ottawa, Gavin Humphries.

“The work we are doing now is just a start, but we are building on other people’s experience,” Navabi says.
Published in Cereals
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