Producing drought tolerant varieties of wheat with negligible impact on yield in good seasons is critical for the success of the Australian farming sector. Avoiding GM will streamline the speed at which new genetic material can be incorporated into breeding programs. There could be improved productivity in dry seasons and regions.
This project aims to develop wheat lines with improved drought tolerance through the identification of plants that lack or have reduced level of SAL1 protein activity which has been implicated as a negative regulator of drought tolerance in the model plant, Arabidopsis (Wilson et al., 2009).
Our previous study (GRDC project # ANU00011) using Chara deletion lines found out that the SAL gene family in wheat was significantly more complex than anticipated, with 7 homeoforms identified rather than the expected 3. However, the presence of seven genes provides the opportunity to identify greater variations in the effects caused by different combinations of mutants and possible fine-tune the drought response. We have identified 12 wheat lines lacking four of the seven SAL1 alleles. A pairwise crossing program involving these mutant lines has been initiated and this in conjunction with the proposed breeding program will enable us to combine double and triple mutants in the seven SAL1 and SAL2 alleles to improve the chances of achieving drought tolerance without any adverse effects. Drought tolerance and yields of these combinations will be characterized under both water-stressed and non-stressed conditions in the glasshouse and in MEF. The best combination of SAL1 mutants may remain green, turgid and photosynthetically active for longer period in water deficit conditions.
The current study is supported by a GRDC grant which runs from 2014-2017.