To develop a novel, robust and rapid process for testing the function of genes thought to be responsible for chloride exclusion and nematode resistance in rootstocks.
Breeding new rootstocks is a time consuming process. Part of the difficulty is in recognising important traits in young plants. Genetic mapping and marker assisted breeding can significantly speed this process. For these techniques to be used, genes or genetic regions carrying the desired traits in rootstocks need to be known. Although previous research has tentatively identified genes in Vitis species that are linked to rootstock stress tolerance and disease resistance, this has not been confirmed.
An excellent way to confirm gene function is to change the expression of the gene in the plant part of interest. This strategy has been used successfully to identify genes relating to berry flavour and colour attributes and for mildew resistance. This is because there are grapevine transformation systems that target genes to leaves and berries. A rootstock transformation system that would allow researchers to test gene function in rootstocks is not yet available in Australia.
The project team will try several different ways to transform rootstocks, including methods used by other researchers, aiming for speed and a high success rate. The usefulness of the method will be demonstrated with the tentatively identified genes of relevance to salt tolerance, and then with other genes as they become available from other projects for other abiotic and biotic stresses. This project thus supports and extends CSP 1302 and CSP 1304; not only will likely genes of relevance for better rootstocks be identified, they will also be confirmed as useful in rootstocks.
The knowledge generated and the genes and markers confirmed 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 and pest and disease resistance will provide more options to grape growers and winemakers to select planting material best suited to their conditions and intended wine style.