Uncovering a Genetic Mechanism to Enhance Yield Potential in Cereal Crops

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Andrea Eveland, Ph.D.

Solving the world’s food, feed and bioenergy challenges requires integration of multiple approaches and diverse skills. Andrea Eveland, Ph.D., assistant member at the Donald Danforth Plant Science Center, and her team identified a genetic mechanism that controls developmental traits related to grain production in cereals. The work was performed in Setaria viridis, an emerging model system for grasses that is closely related to economically important cereal crops and bioenergy feed stocks such as maize, sorghum, switchgrass and sugarcane.

The Eveland laboratory’s research findings, “Brassinosteroids modulate meristem fate and differentiation of unique inflorescence morphology in Setaria viridis”, were recently published in the journal The Plant Cell. In their study, Yang et al. mapped a genetic locus in the S. viridis genome that controls growth of sterile branches called bristles, which are produced on the grain-bearing inflorescences of some grass species. Their research revealed that these sterile bristles are initially programmed to be spikelets; grass-specific structures that produce flowers and grain. Eveland’s work showed that conversion of a spikelet to a bristle is determined early in inflorescence development and regulated by a class of plant hormones called brassinosteroids (BRs), which modulate a range of physiological processes in plant growth, development and immunity. In addition to converting a sterile structure to a seed-bearing one, the research also showed that localized disruption of BR synthesis can lead to production of two flowers per spikelet rather than the single one that typically forms. These BR-dependent phenotypes therefore represent two potential avenues for enhancing grain production in millets, including subsistence crops in many developing countries that remain largely untapped for genetic improvement.

“This work is a great demonstration of how Setaria viridis can be leveraged to gain fundamental insights into the mechanisms that govern seed production in the grasses – our most important group of plants that includes corn, sorghum, rice, wheat and barley,” said Thomas Brutnell, Ph.D., Director of the Enterprise Institute for Renewable Fuels, Danforth Center. “It’s also worth noting that this project was conceived and work initiated after Dr. Eveland joined the Danforth Center – an impressive feat for a junior faculty member that speaks to both the advantages of working on a model system and the great team that she has assembled at the Danforth Center.”

At the Danforth Center, Eveland’s research focuses on the developmental mechanisms that control plant architecture traits in cereal crops. Specifically, she investigates how plant organs are formed from stem cells, and how variation in the underlying gene regulatory networks can precisely modulate plant form. Her team integrates both computational and experimental approaches to explore how perturbations to these gene networks can alter morphology, both within a species and across the grasses, with the ultimate goal of defining targets for improving grain yield in cereals.

“The genetics and genomics tools that are emerging for Setaria enable more rapid dissection of molecular pathways such as this one, and allow us to manipulate them directly in a system that is closely related to the food crops we aim to improve,” said Eveland. “It means we are just that much closer to designing and deploying optimal architectures for cereal crops. The prospect of leveraging these findings for improvement of related grasses that are also orphan crop species, such as pearl and foxtail millets, is especially exciting.”

 

New Survey Identifies Labour Challenges for Seed Growers

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Throughout 2017, a number of seed growers and related organizations voiced concerns about lack of seed grower access to foreign labour through the Government of Canada’s Temporary Foreign Workers Program (TFWP).

To better understand the issue, Canadian Seed Growers’ Association (CSGA) surveyed seed growers across the country. Here are some of the findings:

  • 26% of members surveyed were not able to find all the workers needed to work on their seed farms in 2016 and 2017;
  • When asked what types of workers seed farms need most, 59% of respondents indicated they needed full time permanent positions while 41% indicated they needed seasonal help;
  • 27% of respondents used government programs to access workers;
  • 47% of respondents indicated they would use the Temporary Foreign Workers Program (TFWP) to access season workers if they had access to the program

As a result of these findings, the CSGA began working with the Canadian Seed Trade Association, the Seed Corn Growers of Ontario and the Canadian Agricultural Human Resource Council (CAHRC) to sensitize Government and in particular the Department of Employment and Social Development Canada to the need to expand access to the TFWP to all seed growers.

Initial efforts have focused on ensuring that canola seed growers maintain their current access to the program, that seed corn growers regain the access that they recently (and inexplicably) lost and that other seed growers needs be recognized. While these efforts have not yet yielded results, Government’s initial response has been encouraging.

CSGA will continue to advocate on behalf of members on labour issues and will provide progress reports as discussions with government evolve.

Source: CSGA

Seed Synergy partners launch new website and release Green Paper

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The Seed Synergy Collaboration Project has launched a new website, seedsynergy.net, and released a comprehensive Green Paper proposing a vision for the next generation seed system and inviting comments on it.

Over the past year, leaders from the six major seed sector industry organizations have been working together on the Seed Synergy Collaboration Project to develop recommendations and implementation plans that will enable a next generation seed system for Canada.

“The Seed Synergy partners are pleased to announce these updates to you”, said Krista Erickson, executive director of the Commercial Seed Analysts Association of Canada, speaking on behalf of the group. “Collaboration between the partner groups over the last number of months has brought us one step closer to the reality of a seed system that functions optimally for all those involved in it and for Canadians in general. We hope that agriculture value chain partners will join with us in the discussion and visit our new website today”.

The current model of the seed sector must adapt to seize emergent opportunities. Canada needs a strong vision for the future, and practical reforms now, to position producers, innovators, and ultimately the entire agricultural value chain to succeed in a highly competitive and innovation-based global marketplace.

The Green Paper is the Seed Synergy partnership’s vision for how to meet these challenges, with proposals designed to: stimulate investment to unlock our innovative potential, enable industry to play a greater leadership role in governing the seed system, increase transparency within the system and better meet diverse customer needs and drive growth throughout the agriculture value chain.

Over the coming months the Seed Synergy organizations will be talking to their members, holding regional workshops, and engaging with stakeholders (including key federal government departments) to produce a final White Paper for the spring/summer 2018. The White Paper will chart a course for the future of the seed system, and will set out a strong path forward for industry and government to work together in a meaningful way.

For more details and to provide feedback, visit the new Seed Synergy website.

Self-defense for plants

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This cartoon depicts a leaf with areas of damage (brown spots) caused by the plant’s innate immune response. The superimposed schematic shows SOBER1’s three-dimensional structure. (Courtesy Salk Institute)

Salk scientists characterize unusual plant immune response to bacterial infection

When you see brown spots on otherwise healthy green leaves, you may be witnessing a plant’s immune response as it tries to keep a bacterial infection from spreading. Some plants are more resistant to such infections than others, and plant biologists want to understand why. Salk Institute scientists studying a plant protein called SOBER1 recently discovered one mechanism by which, counterintuitively, plants seem to render themselves less resistant to infection.

The work, which appeared in Nature Communications on December 19, 2017, sheds light on plant resistance generally and could lead to strategies to boost plants’ natural immunity or to better contain infections that threaten to destroy an entire agricultural crop.

“There are a lot of losses in crop yields due to bacteria that kill plants,” says the paper’s senior author Joanne Chory, a Howard Hughes Medical Institute Investigator, director of Salk’s Plant Molecular and Cellular Biology Laboratory and a 2018 recipient of the Breakthrough Prize in Life Sciences. “With this work, we set out to understand the underlying mechanism of how resistance works, and to see how general it is.”

One of the ways plants fight bacterial infection is by killing off their own cells in which bacterial proteins are detected. But some bacteria have evolved a counter strategy—injecting special proteins that suppress the plant’s immune response by adding small, disabling chemical tags called acetyl groups to immune molecules. This process is called acetylation. What makes certain plants able to resist these bacterial counter measures while others succumb to infection remains unclear.

As a means to better understand such pathogen-plant interactions, Chory’s team turned to the well-studied weed Arabidopsis thaliana and, in particular, an enzyme called SOBER1—which had previously been reported to suppress the weed’s immune response to a bacterial protein known as AvrBsT. While it may seem counterintuitive to use immune suppression to study infection resistance, the Salk biologists thought doing so could yield useful information.

The researchers started by determining SOBER1’s amino acid sequence—the particular order of building blocks that gives a protein its basic identity. Intriguingly, they found it was very similar to a cancer-pathway-related human enzyme. This enzyme contains a characteristic tunnel into which proteins with certain types of modifications can fit and be cut as part of the enzymatic reaction. It turns out SOBER1 can be classified as part of a vast protein superfamily known as alpha/beta hydrolases. These enzymes share a common core structure but are very flexible in the chemical reactions they catalyze, which range from the breakdown of fat to the detoxification of chemicals called peroxides.

This image shows four areas of a tobacco leaf in which AvrBsT protein has been produced, along with the normal version of the counter-reacting deacetylase (AtSOBER1, upper left) and several mutant versions. The right side shows SOBER1 mutants in which the newly discovered substrate tunnel has been manipulated. The normal version of SOBER1 has the healthiest-looking tissue, because the plant’s tissue-killing immune response has been blocked by SOBER1.
(Courtesy Salk Institute)

Next, they used a more than 100-year-old technique called X-ray crystallography to determine SOBER1’s three-dimensional structure. While similar to the human enzyme, the plant enzyme’s tunnel had two extra amino acids sticking down from the top: one at the entrance and one in the middle.

“When we saw those, we realized they had to have a dramatic effect on function because they basically block the tunnel,” says Salk research associate and co–first author Marco Bürger.

To discover what the purpose might be, Bürger and co–first author Björn Willige, also a research associate, used substrates (molecules that enzymes act on) with different lengths and biochemically tested how well they fit in the enzyme and whether they could be cut. Only certain types fit and were cut—very short acetyl groups. This suggested that SOBER1 is a deacetylase—a class of enzyme that removes acetyl groups. Furthermore, the team mutated SOBER1 and thus opened the blocked tunnel. With this change, Bürger and Willige engineered an enzyme that lost its strong specificity for short acetyl groups and instead preferred longer substrates.

“For the initial biochemistry experiments, we used established, artificial substrates,” says Willige. “But next we wanted to see what would happen in plants.”

For this, they used tobacco plants—which have large leaves that are easy to work with—and a bacterium with a protein called AvrBsT, known to trigger acetylation. They produced AvrBsT in different regions of tobacco leaves along with SOBER1 and several mutated (and thus nonfunctional) versions of the enzyme.

Leaves producing AvrBsT had brown patches of dead tissue, indicating that AvrBsT had initiated a cell death program to curtail the systemic spreading of the pathogen. Leaves that produced AvrBsT together with SOBER1 looked healthy, indicating that SOBER1 reversed the action of AvrBsT. Strikingly, mutated SOBER1 versions with an opened tunnel were not able to prevent the tissue from dying. From this, the researchers concluded that deacetylation must be the underlying chemical reaction leading to suppression of the plant’s immune response.

The tobacco tests supported the idea of SOBER1 being a deacetylase that would remove acetyl groups added by bacterial proteins. Without the acetyl groups tagging proteins, the plant didn’t recognize them as foreign and thus didn’t mount a cell-killing immune response. The leaves looked healthier because cells weren’t dying.

“SOBER’s function is surprising because it keeps infected tissue alive, which puts the plant at risk,” says Chory, who also holds the Howard H. and Maryam R. Newman Chair in Plant Biology at Salk. “But we are just beginning to understand these types of mechanisms, and there could very well be conditions in which the actions of SOBER1 is beneficial.”

Further tests showed that the activity and function of SOBER1 is not restricted to the weed Arabidopsis thaliana, but also exists in a plant called oilseed rape demonstrating that the findings of Chory’s lab could be applied to agricultural crops and biofuel resources.

Bürger and Willige would next like to begin screening for chemical inhibitors that could block SOBER1, thereby allowing plants to have a full immune response to pathogenic bacteria.

The work was funded by Howard Hughes Medical Institute, Deutsche Forschungsgemeinschaft, the Human Frontier Science Program and The Pioneer Postdoctoral Endowment Fund.

Flax Council of Canada Closing Its Doors

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After 32 years of representing the interests of all agricultural and industrial flax interests, the Flax Council of Canada’s executive committee announced yesterday the closure of its office in Winnipeg, effective Jan. 31, 2018. The Flax Council of Canada will continue to operate on a reduced service basis.

The Flax Council of Canada is a national organization, funded by a voluntary export levy. Established in 1986, the Flax Council promotes the advancement of Canadian flax and flax products including nutritional and industrial uses in domestic and international markets.

In a news release, the Flax Council stated: “Over the course of the past year, the formation of a combined oilseed council was thoroughly discussed at the request of some of our members that contribute significant levy dollars to the Council. Through these discussions, it became apparent that the formation of an oilseed council would not materialize in the foreseeable future. The result of this is a significant loss of funding to the Council, necessitating cost reduction measures.”

Recognizing the importance of a national voice, the news release went on to state further dialogue will be needed to see what opportunities may lay ahead as the flax industry decides the merit of a national organization.

The Flax Council played a key role in managing the aftermath following the detection of CDC Triffid seed in shipments to the EU, providing financial support to significant testing protocols in an effort to remove Triffid from the seed supply in Canada.

Since 2013, the Flax Council has managed more than $6.2 million in research and market development programs with the support of Agriculture and Agri-Food Canada, Manitoba Agriculture, Saskatchewan Ministry of Agriculture, and both the Saskatchewan Flax Development Commission and Manitoba Flax Growers Association.

David Sippell Joins Cibus to Lead Canadian Operations

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Cibus, a leading trait development and plant breeding company, has appointed David Sippell as Vice President, and General Manager, Canada. He will manage Canadian operations from Cibus’ new office in Winnipeg.

Sippell has more than three decades of experience within the agribusiness sector. With the recent launch of SU Canola in Canada, Sippell will direct Cibus’ growth and expansion into the Canadian canola market.

“David’s addition to the Cibus team as the leader of our Canadian operations will steer the company’s progress in this geography and provide innovative profit-yielding options to Canadian farmers,” said Peter Beetham, Ph.D., President and Chief Executive Officer, Cibus. “David’s extensive knowledge of the seed business and international agribusiness expertise will strengthen and grow Cibus’ expanding presence in the world’s most valuable canola seed market.”

David Sippell

Sippell will bolster Cibus’ growing commercial team. “David’s expertise in the agribusiness sector and his deep knowledge and passion for the canola industry will contribute to the expansion of Cibus’ operations in Canada,” said Bradley Castanho, Ph.D., Senior Vice President, Commercial and Business Development.

Sippell’s experience includes decades of leadership experience in the canola seed business in Canada with a range of companies that include Pioneer Hi-Bred International Inc. and Syngenta, and Sippell was the founding President and CEO of Canterra Seeds Holdings Ltd., a grower-owned seed company. Sippell holds a Bachelor of Science, Master of Science and Doctor of Philosophy in Plant Pathology and Plant Breeding from the University of Guelph.

According to a news release, SU Canola offers Canadian growers valuable, non-GMO hybrids that provide a new option for weed control. Cibus’ first canola hybrid was registered for sale in Canada in spring 2017. Led by Sippell, Cibus’ Winnipeg office is the flagship for expanding Canadian operations as Cibus launches its expanding product portfolio.

Agrium and PotashCorp Merger Completed Forming Nutrien

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Nutrien Ltd. today announced the successful completion of the merger of equals between Agrium Inc. and Potash Corporation of Saskatchewan Inc., creating the world’s premier provider of crop inputs and services.

According to a news release, Nutrien has the largest crop nutrient production portfolio combined with a global retail distribution network that includes more than 1,500 farm retail centres. With nearly 20,000 employees – and operations and investments in 14 countries – the company is committed to providing products and services that help growers optimize crop yields and their returns.

“Today we are proud to launch Nutrien, a company that will forge a unique position within the agriculture industry,” said Chuck Magro, president and chief executive officer of Nutrien. “Our company will have an unmatched capability to respond to customer and market opportunities, focusing on innovation and growth across our retail and crop nutrient businesses. Importantly, we intend to draw upon the depth of our combined talent and best practices to build a new company that is stronger and better equipped to create value for all our stakeholders.”

Nutrien Board of Directors and Senior Leadership Team

Nutrien’s board of directors has equal representation from Agrium and PotashCorp. Jochen Tilk will serve as the executive chair, with Derek Pannell as the board’s independent lead director. Rounding out Nutrien’s senior leadership team is Wayne Brownlee, executive vice president and chief financial officer, and Steve Douglas, executive vice president and chief integration officer.

Additional members of Nutrien’s senior leadership team include:

  • Harry Deans, executive vice president and president, nitrogen
  • Michael Frank, executive vice president and president, retail
  • Kevin Graham, executive vice president and president, sales
  • Susan Jones, executive vice president and president, phosphate
  • Lee Knafelc, executive vice president and chief sustainability officer
  • Leslie O’Donoghue, executive vice president and chief strategy and corporate development officer
  • Joe Podwika, executive vice president and chief legal officer
  • Brent Poohkay, executive vice president and chief information officer
  • Raef Sully, executive vice president and president, potash
  • Mike Webb, executive vice president and chief human resources officer

 

New limits to clothianidin and thiamethoxam use

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(Photo: Janet Kanters)

Health Canada announced new mitigation measures today on the neonicotinoids​ clothianidin and thiamethoxam, pesticides which are sold as seed treatment or sprays to protect agricultural crops from various insects.

A statement from the Grain Growers of Canada said modern grain farmers “utilize a diverse and innovative toolbox of crop protection products, including neonicotinoids.”

The statement says clothianidin and thiamethoxam “are not expected to affect bees,” when used as a seed treatment — a view many environmental organizations dispute.

READ the CBC story

The PMRA is updating the pollinator risk assessment for imidacloprid based on additional data from the registrant, additional literature that has recently been published, and the comments that were received during the public consultation period for the preliminary assessment (REV2016-05, Re-evaluation of Imidacloprid – Preliminary Pollinator Assessment). The PMRA expects to publish a proposed decision regarding imidacloprid pollinator safety in March 2018.

Read more on the proposed clothianidin and thiamethoxam re-evaluation decisions:

 

Midge Tolerant Wheat Stewardship Goes Online

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New system simplifies process for protecting midge tolerance.

Growers of midge tolerant wheat are accustomed to putting pen to paper and signing a stewardship agreement with their seed retailers every year. All of that changes this growing season as the Midge Tolerant Wheat Stewardship Team has launched a digital platform and evergreen agreement. The move online is expected to improve the process for growers and retailers, and help ensure continued protection of the midge tolerance gene.

The Midge Tolerant Wheat Stewardship Assurance Site (MTWSAS) is a secure, web-based tool for use by seed distributors, seed retailers and seed growers that makes the process of documenting the movement of certified midge tolerant wheat seed more efficient. It allows users to create electronically signed stewardship agreements and to post sales transactions.

Digital Agreement is Evergreen

“The new system creates a state-of-the-art means of managing midge tolerant wheat stewardship while also making the process very efficient for everyone who utilizes this valuable technology,” says Rod Merryweather, CEO of FP Genetics, one of the six official distributors of midge tolerant wheat in Western Canada. “It is a big step forward in protecting this valuable trait so resistance does not develop,” he adds, noting that midge tolerant wheat continues to deliver “$36 per acre of value to those who use it each and every year.”

All midge tolerant wheat is sold to farmers under an agreement in order to ensure proper stewardship of the technology, which limits the use of farm-saved seed to one generation past certified seed. With MTWSAS, the stewardship principles do not change, but the process becomes a lot easier.

“This online agreement replaces the paper-based version and manual process that we’ve used since the launch of midge tolerant wheat in 2009,” explains Mike Espeseth, communications manager for the Western Grains Research Foundation and co-chair of the Midge Tolerant Wheat Stewardship Committee.

“The online stewardship agreements are evergreen, which really simplifies things for everyone. Agreements are now signed digitally and farmers will only need to sign once, no matter where they buy their seed,” he says.

System Provides Savings for Retailers

While stewardship agreements have been a vital part of protecting midge tolerant wheat technology for the past eight years, Espeseth and the team knew the process could be improved.

“The new MTWSAS is simple and technologically advanced,” says Ed Mazurkewich, a business development consultant with AgCall, the developer and host of the new retailer-driven platform.

“All wholesale and retail movement of certified midge tolerant wheat seed is posted to the MTWSAS by seed growers and retailers with a user-friendly interface,” he says.

Merryweather anticipates the new process will save time and money for retailers. It will eliminate the nuisance of duplicate agreements and add report-generating capabilities for their specific varieties.

“MTWSAS enables them to manage their customer base and create reports that will help them to manage current and future sales of products,” he says. “It will also eliminate the onerous task of accumulating data for each farmer.”

Merryweather adds that distributors can expect to benefit as well. “We will have access to complete information on the sale of all of our products, along with the absolute confidentiality we need in our business and for our farm and seed grower customers,” he says. MTWSAS is administered and managed by AgCall with oversight by the Canadian Plant Technology Agency to ensure privacy and confidentiality.

Shining a Light on Stewardship

An added bonus of the new system is that it serves as a good reminder to growers and retailers on the vital need for stewardship.

In a survey conducted in spring 2017 with more than 1,000 wheat growers in Western Canada, 94.1 per cent of Alberta growers agreed that “it is critical to have a stewardship program in place to ensure that the effective life of the midge tolerance gene is protected.” The survey also found that 95.1 per cent are familiar with the stewardship agreement for midge tolerant wheat. However, results showed new growers are less familiar with the agreement than existing growers.

“The new system enables us to identify any grower who may be out of compliance so we can follow up,” says Merryweather. “The key is we have the tools to protect this valuable technology and to keep it working for farmers for many years to come.”

Accessing the New System

Mazurkewich explains that in order for distributors, retailers and seed growers to access the new system, they require a new authorized retailer number. This is obtained by successfully passing the updated retailer training located at midgetolerantwheat.ca and by signing a new retailer stewardship agreement at MTWSA.ca.

“New processes incur new actions and perhaps new questions,” says Mazurkewich, adding AgCall is committed to providing ongoing support. “Users will have access to four videos outlining how to use MTWSAS once they receive their login information.”

Crop Gene Discovery Gets to the Root of Food Security

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Researchers from The University of Queensland have discovered that a key gene which controls flowering time in wheat and barley crops also directs the plant’s root growth.

Project leader Dr. Lee Hickey from the Queensland Alliance for Agriculture and Food Innovation(QAAFI) said the discovery was a major breakthrough in understanding the genetics of root development and could boost food security by allowing researchers to breed crops better adapted to a range of environments.

“Wheat and barley are ancient crops and humans have been growing them for thousands of years,” Hickey says. “Over the years, farmers and more recently plant breeders, have made significant progress selecting for above-ground traits, yet have largely ignored the ‘hidden half’ of the plant – its roots.

“Our discovery that the VRN1 gene, which is known to regulate flowering in wheat and barley crops, also plays a role in the plant’s ability to respond to gravity, thereby directing root growth and determining the overall shape of the root system.”

Hickey says this unexpected insight into the underground functions of the VRN1 gene has major implications for optimizing cereal crops, as crop varieties with improved root systems could dramatically improve farm productivity.

“A particular variant of VRN1 in barley, known as the Morex allele, simultaneously induced early flowering and maintained a ‘steep, cheap and deep’ root system,” Hickey says.

“This is exciting because flowering time is a key driver for yield and the VRN1 gene appears to offer a dual mechanism that could not only boost crop yield but also improve water and nutrient acquisition through a deeper and more efficient root system.”

The root gene discovery was part of an international collaboration with a team of scientists from Justus Liebig University in Germany, led by Professor Rod Snowdon. The group in Germany provided insight of the gene’s involvement in shaping root development for winter wheats grown throughout Europe, as well as validation of rooting behaviour in field trials.

Another collaborator was Dr. Ben Trevaskis from CSIRO who provided important experimental wheat and barley materials critical for validating the gene’s role in root development.

PhD student Hannah Robinson, along with Dr. Kai Voss-Fels who has recently joined QAAFI as a Research Fellow were joint first authors for the study published this week in high impact journal Molecular Plant.

“While our discovery is exciting, more research is needed to identify other key genes involved to effectively optimise root growth in future crops for farmers,” Robinson says.

“Also, we need to determine the preferred root system architecture for different growing regions, which will help plant breeders develop more productive crops, despite the increased variability of future climates,” she says.

The cereal root research at The University of Queensland and wheat phenology research at CSIRO is supported by the Grains Research Development Corporation, and Robinson’s PhD scholarship.

Source: University of Queensland