Genetic and mechanistic characterisation of rootstock traits conferring abiotic stress tolerance to grapevines
To identify molecular markers responsible for abiotic stress tolerance in rootstocks.
Climate change is expected to result in increased temperatures and more extreme weather events. This has the potential to impact water availability and soil salinity. Resilient rootstocks, capable of dealing with climatic extremes and salt stress are essential in ensuring continued quality grape and wine production.
Previous research has tentatively identified genes in Vitis species that are linked to stress tolerance but this has not been confirmed and markers that could be used for breeding these traits in Vitis rootstocks are therefore not available. How these genes make rootstocks more stress tolerant is also not known.
Rootstock cuttings generated from a cross between Vitis cinerea and V. vinifera will be exposed to a range of abiotic stresses and water use efficiency, and drought, heat and salt tolerance will be assessed. Analysis of the genes expressed in the cuttings will identify markers for heat, drought and salt tolerance. A subset of these cuttings will be grafted to Shiraz and also assessed under the stress conditions, to validate whether screening ungrafted rootstocks correctly predicts how the rootstocks would perform when grafted. In parallel, experiments to understand the mechanisms of salt exclusion and heat tolerance will be undertaken to validate and further confirm the markers to be used for screening are appropriate.
The knowledge generated and markers identified in this project will allow grapevine breeders to be faster and more targeted in future rootstock breeding programs. More water efficient rootstocks with heat and salt tolerance will provide more options to grape growers and winemakers to select planting material best suited to their conditions and intended wine style.