Australia
June 8, 2025
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Oat phenology researcher Dr Meredith McNeil at CSIRO in Canberra. - Photo: Rohan Thomson
Key points
- Tailored adaptation: Flowering time variation helps growers and breeders adapt oats to diverse environments, climates, sowing schedules and management practices
- Rich genetic diversity: The OzOat panel captures a wide range of flowering behaviours, providing a strong foundation for breeding better-adapted oat varieties
- Breeding tools: Genetic markers for oat phenology genes enable breeders to efficiently transfer desirable traits into elite lines
- Elite germplasm: Elite oat lines with enhanced flowering time genetics delivered to breeders
- Future opportunities: Novel trait combinations support the expansion of oat production into new regions and offers greater sowing flexibility
Researchers identify genetic variation, enabling breeders to create better-adapted sowing options for growers
Shifting sowing dates can be a simple but effective adaptation strategy to cope with new environments, leading to better crop performance and increased yields.
To better harness these advantages in oats, a GRDC investment with CSIRO has generated elite lines containing newly discovered variation in flowering time genetics.
The project was launched following the success of modulating flowering time or ‘phenology’ traits in other crops. The approach proved a viable way to boost yield, yield resilience and quality while also diversifying crop rotations.
However, little was known about flowering time genetics in oats, even as the importance of the crop was increasing in Australian farming systems.
In response, GRDC invested in the pre-breeding project initially conceived and headed by CSIRO’s Dr Ben Trevaskis and now led by Dr Meredith McNeil. Project partners included Scott Boden at the University of Adelaide, Felicity Harris at Charles Sturt University and Allan Rattey at Intergrain.
Together, the team successfully characterised and delivered to industry a diversified range of oat phenology traits. The bolstered genetic toolkit was delivered to breeders at the end of 2024. It will enable breeders to better adapt oat cultivars to different environments, climates, sowing plans and management practices.
Meredith McNeil. Photo: Rohan Thompson
Breakthrough
Dr McNeil says that the newly discovered traits create novel opportunities to mitigate the risk of late frosts and terminal drought in different environments.
They ultimately allow more growers to access the rotation benefits provided by oats – namely, system flexibility.
“Oats can be used for grazing, hay production and as a cover crop in addition to producing grain valued for its protein and soluble fibre content,” Dr McNeil says.
“As a break crop, oats also help to break disease cycles, manage weeds and improve soil health. Importantly for some growing regions, oats can withstand frost.”
In Australia, oat is the fourth-largest cereal crop, valued at $270 million in 2022, with Australia the second-largest oat exporter after Canada.
As usual when taking a genetic approach to solve farming system problems, the endeavour began by gathering a collection representative of the world’s most appropriate genetic diversity.
Diversity panel OzOats
At the project’s outset, researchers assembled Australian and international oat varieties in a diversity panel called OzOats. Ancestry and pedigree provided the framework for the selections.
For Australian oats, this involved collating the breeding history in a pedigree database that records the parentage of modern oats. This pedigree database includes more than 1000 oats and extends back to the earliest modern oats, circa 1892.
This approach enhanced the ability to dig down and identify genetic differences responsible for valuable traits.
In other words, it enhanced the resolution of genetic maps.
Using an overview of global breeding pedigrees, a panel of about 300 oat accessions was selected to form a ‘core population’ for genetic analyses.
“The accessions have been chosen to capture genetic diversity, but also a high degree of gene shuffling (recombination), which facilitates genetic analyses,” Dr McNeil says.
“The OzOat panel was then characterised for flowering time characteristics.”
Experimental scientist Tina Rathjen and Dr Meredith McNeil are working to help breeders better adapt oat cultivars to different environments, climates, sowing plans and management practices. Photo: Rohan Thompson
Flowering trials
To characterise the phenology of the OzOats material, the lines were first grown in controlled environment glasshouse experiments to isolate the effects of daylength and vernalisation on flowering time.
A subset of about 80 lines were grown in field conditions at Wagga Wagga, New South Wales, to validate the findings. The trial was sown at two dates in 2021 (7 May and 2 June) and three dates in 2022 (14 April, 3 May and 24 May).
The timing of different developmental stages, such as panicle emergence, anthesis and plant maturity, were recorded.
Notably, modern Australian varieties (post-2000) were found to be largely made up of spring oats. However, winter oat genetics were identified by the team for transfer into Australian varieties.
The trials confirmed that the OzOat panel captures a wide range of flowering behaviours and is more diverse than modern Australian oats.
“This provides a good starting point to breed new Australian oats with flowering behaviours suited to the needs of emerging farming practices, such as earlier sowing.” Dr McNeil says.
Flowering time breeding tools
The newly identified phenology traits were mapped onto the oat genome using a Genome Wide Association Study. This was done on the whole OzOat panel in controlled environment conditions and a subset of the panel was grown under field conditions.
The subset of genes that are expressed at different stages of development – called the transcriptome – was also analysed. This data was processed using machine learning models to help identify individual genes and their role in phenology response.
“No single major-effect gene was identified, indicating that phenology is controlled by multiple moderate to small-effect genes that vary across varieties,” Dr McNeil says.
Importantly, this work produced evidence that oat’s photoperiod sensitivity (to lengthening daylength in spring) includes unique genetic elements compared with wheat and barley.
A GRDC investment with CSIRO has generated elite lines containing newly discovered variation in oat flowering time genetics. Photo: Rohan Thompson
Trait transfer
Researchers developed markers that directly select for the newly identified oat phenology genes.
The markers were used to develop a population of near-isogenic lines (NILs) that are genetically similar except for differences at the phenology genes.
Breeding for the NILs was accelerated by Intergrain, which made its oat speed-breeding facilities available during the project.
In the form of NILs, the phenology traits can be readily transferred into elite breeding lines, using markers to select for the desirable variants.
To facilitate uptake, a total of 37 NILs are available on request to CSIRO via a GRDC Material Transfer Agreement (MTA).
Looking ahead, Dr McNeil says the project outputs can also be used to create entirely new combinations of phenology traits. This could result in even better-adapted varieties or varieties suited to new growing areas.
“Oat varieties with improved phenology stand to give farmers greater flexibility and additional management tools,” she says.
“For example, it allows the inclusion of oats in a greater variety of sowing plans.
“But it also allows for more informed planting decisions based on market demands and environmental conditions.”
As the phenology traits are tested in more environments, the knowledge gained can be used to develop predictive models. These would allow growers to forecast flowering or maturity dates for specific oat cultivars, at different location and sowing date combinations.
When it comes to trait discovery efforts more generally, the OzOats panel is not restricted to phenology. Instead, its validated genetic diversity can find ongoing applications for additional trait discovery work. For example, the panel has already found applications in a GRDC investment (CSP2204-007RTX) targeting oat crown rust.
Importantly, CSIRO researchers have delivered a tool that can help sustain and accelerate gains in oat productivity, sustainability and profitability.
More information: Meredith McNeil, meredith.mcneil@csiro.au
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