Output 1: By 2030, elite germplasm available to Australian breeders with combinations of existing genes for heat-stress resilience at flowering and grain filling.
Description:
- Highest performing, large effect QTLs are identified that confer improved heat tolerance (eg. maintenance of grain plumpness, minimisation of grain screening, and higher spikelet fertility) and their stability validated across multiple environments.
- Single and multiple thermo-resilient gene combinations in adapted backgrounds that provide at least a 5% yield improvement under heat-stress events occurring at either flowering or grain filling stages [or both], and no yield penalty under non-stressed conditions compared to the current highest yielding cultivars.
- Elite germplasm, all associated data, and breeder-deployable molecular markers to be delivered to Australian barley breeders via the GRDC Approved Breeders MTA.
Output 2: From 2028 new sources of heat-stress resilience are identified and relevant molecular markers are delivered to Australian breeding companies.
Description: At least 10-15 new sources of heat tolerance/resistance are identified, introgressed into Australian adapted genetic backgrounds, and evaluated under multi-environmental trials then delivered to breeders along with specific markers under the GRDC Approved Breeders MTA.
Output 3: By 2030, genes and mechanisms for heat-stress resilience at different barley developmental stages identified.
Description: Dissect the molecular mechanisms (and casual genes) driving thermo-resilience in the ‘best-bet’ sources for grain plumpness and spikelet fertility to better inform pyramiding strategies and targets for gene editing.
Output 4: By 2030, the Australian pre-breeding and breeding community are provided with genomic and performance information on barley heat resilience genetics, novel high throughput cost effective tools to phenotype heat resilience, and methods/information for best combining and tracking heat resilience sources.
Description:
- Refine the precision and affordability of phenotyping heat stress. This would involve improved protocols for implementing time specific heat stress events (e.g. using heat chambers/polyhouses, and in-field heat chambers); development of high-throughput low-cost proxy measures (tolerance indicators) for normally difficult to measure physiological traits (e.g. metabolite marker, hyperspec, NIR, etc.); and methods to more easily phenotype otherwise laborious traits, for example, X-ray CT scans to study undissected barley heads and measure unfertilised ovule numbers, aborted grain numbers, and extent of grain fill.
- Use these ‘easier/faster' protocols to better interrogate ‘best-bet’ thermo-resilience sources, for example, determining heat load ranges of best bet sources, pushing them to their extremes to exactly define the extent of their thermo-resilience.
- In the latter years of the project, take the top candidate thermo-resilient sources and characterise them further for grain quality attributes (e.g. malting, brewing, and feed attributes) using established high-throughput proxy techniques (i.e. NIR).
- Provide genomic breeding tools (thermo-resilient genetic catalogue, quality and yield performance database, breeder-deployable markers, prediction model, whole genome selection, AI-informed gene pyramiding designs) to support breeders in the development of varieties with broadly applicable heat stress resilience via the GRDC Approved Breeders MTA.