CAIGE targets traits adapted to Australian growing conditions

CAIGE restructure delivers step-change in germplasm acquisition from international breeding programs

Crops
CAIGE leader Professor Richard Trethowan implemented a new approach to germplasm acquisition targeting crop traits adapted to Australian growing conditions when he travelled across Morocco, North Africa, in 2019. PHOTO Clarisa Collis

CAIGE leader Professor Richard Trethowan implemented a new approach to germplasm acquisition targeting crop traits adapted to Australian growing conditions when he travelled across Morocco, North Africa, in 2019. PHOTO Clarisa Collis

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New CAIGE structure sees plant breeders 'cherry-pick' Australia-specific crop traits.

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A dimensional portal is anything you want it to be ... a doorway connecting distant lands, even the genetic traits for crop variety improvement in those lands.

In Australia, the grains industry equivalent of such a portal is the CIMMYT Australia ICARDA Germplasm Evaluation (CAIGE) project, which functions as a gateway to international crop germplasm and its breeding programs.

Now this doorway connecting the Australian plant breeding community to genetic crop diversity and elite germplasm in countries around the world has been reimagined as part of a GRDC-invested restructure.

University of Sydney Professor Richard Trethowan, who has led the project since its inception in 2006, examines the new architecture of CAIGE, including a step-change in its functionality and scope as part of the restructure last year.

Professor Trethowan says the project's new design is venturing to new depths within multinational germplasm collections to discover genetic traits specifically adapted to Australian growing conditions.

It achieves this objective through a targeted approach to germplasm selection that sees collaborators that contribute to the CAIGE network, particularly plant breeders from private companies, "cherry-pick" Australia-specific crop traits from overseas breeding programs.

Professor Trethowan estimates that the new Australia-centric approach to germplasm acquisition could lift the return on investment that CAIGE delivers to Australian grain growers, mainly through improved crop variety development, by about 30 per cent.

"We have increased the probability that any one plant line brought into the country through the project will have better value for industry," he says.

The new traits adapted to Australian farming systems are being drawn from the vast assemblage of genetic material at the International Center for Agricultural Research in the Dry Areas (ICARDA) in Morocco and the International Maize and Wheat Improvement Center (CIMMYT) in Mexico.

"Every single plant line that we bring into the country now has a higher probability, on average, of meeting Australian requirements because we are selecting it specifically for Australian traits and characteristics, which means better value for our industry." - University of Sydney Professor Richard Trethowan

INTERNATIONAL EXPEDITION

InterGrain national early generation plant breeder, Dr Allan Rattey, was part of a CAIGE contingent that travelled to Morocco in search of Australia-specific crop traits in April last year. PHOTO Clarisa Collis

InterGrain national early generation plant breeder, Dr Allan Rattey, was part of a CAIGE contingent that travelled to Morocco in search of Australia-specific crop traits in April last year. PHOTO Clarisa Collis

A CAIGE contingent of Australian plant breeders, led by Professor Trethowan, can be found searching for these genetic gems in the countryside of Morocco or Mexico each year.

The CAIGE team, usually comprising "three or four representatives from different breeding companies or regions", alternates between travelling to ICARDA in April one year and CIMMYT in March the following year in a continuous cycle of annual field trips.

GroundCover was in Morocco in April last year when Professor Trethowan and Intergrain national early generation plant breeder, Dr Allan Rattey, implemented the new approach to germplasm acquisition as part of the CAIGE structural change.

Together with ICARDA senior wheat breeder Dr Wuletaw Tadesse, they travelled from north to south across the African country, searching ICARDA trial sites at Marchouch, Settat and Marrakesh for crop traits suited to Australian conditions.

"There's a lot of footslogging and getting out in the field to examine and discuss the genetic material.

"It's also incredibly valuable when you can walk with the (ICARDA) breeder examining the plant lines," he says of the genetic insights provided by Dr Tadesse that helped guide trait selection in 2019.

Professor Trethowan says plant lines selected from the field are then examined against the backdrop of ICARDA and CIMMYT plant breeding databases containing "vital information" on crop characteristics, such as yield, quality and physiology, including traits for resistance and tolerance.

"We go deep inside the breeding programs," he says. "We're not just looking at the advanced breeding material that is released globally.

"We are looking right back at the early stages of breeding programs for genetic nuggets that might have been thrown out because the traits were not relevant to ICARDA and CIMMYT client countries in the developing world."

STRUCTURAL CHANGE

The Australian plant breeding community previously received fixed consignments of seed containing elite germplasm matched to different growing conditions and constraints in developing countries. PHOTO Clarisa Collis

The Australian plant breeding community previously received fixed consignments of seed containing elite germplasm matched to different growing conditions and constraints in developing countries. PHOTO Clarisa Collis

Under the previous CAIGE structure, the Australian plant breeding community received fixed consignments of elite germplasm, which breeders at ICARDA and CIMMYT developed using genetic characteristics matched to countries in the developing world.

"Those fixed consignments or nurseries of advanced breeding lines were targeted to the different growing conditions and constraints in developing countries such as India, Pakistan and North Africa," Professor Trethowan says.

Sometimes, however, "personal selections" of genetic material, chosen for their Australian context, were added to the fixed consignments of seed brought into the country and processed through quarantine each year via the CAIGE project.

Professor Trethowan says that, on average, these lines were found to perform better in Australian trials, highlighting the potential for a targeted approach to germplasm selection in helping to develop more productive and profitable crop cultivars for growers.

"Every single plant line that we bring into the country now has a higher probability, on average, of meeting Australian requirements because we are selecting it specifically for Australian traits and characteristics, which means better value for our industry," he says.

COLLABORATION LIFT

Professor Trethowan says the new CAIGE structure has stimulated increased collaboration in the project. PHOTO Clarisa Collis

Professor Trethowan says the new CAIGE structure has stimulated increased collaboration in the project. PHOTO Clarisa Collis

The scope of CAIGE's Australian trial program, in which international germplasm is road-tested at sites across the country, has also expanded through the GRDC-invested restructure.

Professor Trethowan says the trial program expansion is an unexpected consequence of the transition to a new system, which restricts access to data from trials run privately by breeding companies to CAIGE collaborators.

In other words, only organisations that run their own trials to test the performance of the imported germplasm in this country, and contribute their findings to the CAIGE network can access the full, collective pool of Australian trial data.

In the past, this data was publicly available, but now it is password-protected on the CAIGE website, with passwords only provided to project collaborators.

Professor Trethowan says "FOMO" (fear of missing out) on the full data set gleaned from the trials has stimulated increased participation in the CAIGE project.

For instance, the number of Australian trial sites has doubled since the restricted-access system was announced, he says.

Collaborators contributing to the 2019 trial program for wheat (bread and durum) and barley included the University of Sydney, Murdoch University, University of Queensland, University of Adelaide, New South Wales Department of Primary Industries, Australian Grain Technologies, LongReach Plant Breeders, InterGrain, Edstar Genetics, S&W Seed Company and BASF. Rebel Seeds is also expected to run trials in 2021.

However, data from GRDC-funded CAIGE yield trials in Australia, as well as the findings of quality and disease screening, are still publicly available via the website.

More information: Richard Trethowan, richard.trethowan@sydney.edu.au; www.caigeproject.org.au

Professor Trethowan addresses crop scientists at ICARDA's Marchouch Research Station near Rabat, Morocco. PHOTO Clarisa Collis

Professor Trethowan addresses crop scientists at ICARDA's Marchouch Research Station near Rabat, Morocco. PHOTO Clarisa Collis

ABOUT ICARDA

Established in 1975, ICARDA is an international R&D organisation that aims to improve food, nutritional and water security, lift environmental health and reduce poverty in dry areas of the world facing climate challenges.

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NOTE: Clarisa Collis travelled to Morocco, North Africa, with assistance from the Crawford Fund, as the winner of the Crawford Fund Food Security Journalism Award.

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