Enhancing barley resilience to heat stress
Project name and code
Maintenance of grain plumpness and transfer of heat tolerance into Australian barley germplasm (cultivars)
Code
UMU00049
Threats to crop yields
Heat stress poses a major challenge to sustainable crop production in Australia.
In 2015, high-temperature stress during the grain filling stages, including unseasonal high temperatures in early October within the Australian grain belt, resulted in approximately $500 million in grain production losses, equating to about 6 per cent.
Since 1950, the average temperature has risen by 0.9 degrees Celsius, with predictions indicating a further increase of 2-3 degrees Celsius and a 20-30 per cent reduction in rainfall in the grain belt over the next 20 years.
These climate changes and the increased frequency of heatwaves are expected to exacerbate economic damages to all major crops. In barley, heat stress leads to reduced grain plumpness and grain yield loss.
Grain plumpness, a key indicator of potential malt quality, has become a critical factor in downgrading malting barley to feed barley, resulting in up to a 30 per cent loss in market value for Australian barley growers.
This project was initiated by Murdoch University, the Western Australian Department of Primary Industries and Regional Development (DPIRD), InterGrain, and Australian Grain Technologies (AGT).
It is a consortium which brings together scientists from various disciplines to address the impact of heat stress on grain plumpness in barley during the grain filling stage.
The primary aim of the project was to identify barley germplasm, physiological traits and associated genomic regions tolerant to heat stress during the grain-filling stage. The objectives included:
- Sourcing novel barley germplasm for heat stress tolerance.
- Identifying physiological traits associated with heat stress tolerance.
- Identifying genomic regions and QTLs associated with heat stress tolerance.
The project aimed to deliver 3 key outputs:
Output 1 – identification and validation of effective and new sources of heat-tolerant barley germplasm from landraces, obsolete cultivars, wild relatives, and existing populations, including CIMMYT and ICARDA germplasm.
Output 2 – identification of physiological traits and associated phenotyping tools that correlate with heat tolerance, making them available to breeders.
Output 3 – identification of molecular markers or genes for heat tolerance, making them available to breeding programs in adapted germplasm, along with markers for major QTLs for marker-assisted selection.
Professor Chengdao Li said the outputs were delivered through several milestones, which facilitated studies on diverse barley germplasm under natural and controlled environments across seasons and regions.
“Researchers evaluated over 1200 barley germplasm of diverse origins, including single seed descent (SSD) lines from biparental crosses, Near Isogenic Lines (NILs) previously reported for root traits and tolerance to abiotic stress, international germplasm from ICARDA, current and historical Australian barley varieties, and non-commercial breeding lines from various Australian programs.
The project assessed highly diversified barley germplasm across more than 50 different environments to address complex genotype by environment interactions and identify novel germplasm and genomic regions associated with heat stress tolerance during the grain-filling stage.
Significant achievements
There were several significant achievements measured. These included:
Identification of novel germplasm and genomic regions linked to heat stress tolerance.
Genome-Wide Association Studies (GWAS) of 779 international barley germplasm identified approximately 69 highly significant QTL linked with grain plumpness using a 2.5mm sieve in 11 environments, and 39 QTL linked with grain screenings using a 2.2mm sieve in 5 environments.
These achievements will support the development of barley varieties with improved grain plumpness and stability, thereby increasing the reliability of malting barley supply.
New varieties with enhanced grain plumpness under heat stress conditions, compared to current benchmarks like Bass and Compass, will benefit Australian barley growers by reducing economic losses due to unpredictable and prevalent heat stress during the grain filling stage.
Continued research, incorporating newly developed genomic and pangenome resources of barley germplasm from Australia and international sources, including wild barley, will further enhance these achievements.
Funding partners / project collaborators
Australian Grain Technologies (AGT)
Murdoch University
InterGrain
Contact
Professor Chengdao Li
DPIRD Senior Principal Research Scientist and Director of the Western Crop Genetics Alliance
E: Chengdao.Li@dpird.wa.gov.au
P: 0427 386 141