Methods for evaluation of DROught Stress Tolerance in VCU testing

The climate crisis poses challenges for Austrian agriculture. Quality wheat is mainly grown in dry regions of eastern Austria, where the yield is heavily dependent on the water supply. Maize has also suffered more from drought stress in recent years and increasingly needs to be irrigated. In addition, climate models are forecasting longer periods of drought for Austria, which will have a major impact on cultivation. One solution is new varieties with improved drought tolerance. Until now, farmers have had to rely on information from company brochures, as there is still no standardized assessment in variety value testing. The official protocols only record parameters such as leaf rolling and ear sterility, which are not suitable for assessing variety performance under drought stress. Currently, yield in regions with low precipitation remains the only orientation, but a precise indicator for drought stress tolerance is missing. In order to be able to make a meaningful assessment of drought resistance, suitable methods are required. The aim of the project is to test innovative methods, evaluate their suitability for variety value testing and thus establish sustainable variety testing. In this study, three dry locations in eastern Austria are selected. In addition, a “rain-out shelter” is used to specifically increase drought stress. Soil moisture monitoring using soil sensors will provide precise data on the extent of the drought. In addition, the soil quality and water retention capacity will be determined. These measures make it possible to assess both the degree of drought stress and the suitability of the sites. Modern phenotyping methods such as near-infrared spectrometers and drones with special cameras are used to record the influence of water shortage on the health and metabolic activity of the plants. Similarly, the proteome of the grains at various stages of development is also examined using high-resolution mass spectrometry. The quantification of important metabolic enzymes and heat indicators (e.g. heat-shock proteins) can provide information on how the individual varieties behave under drought stress. The data obtained makes it possible to find the most suitable methods. A final evaluation using a SWOT analysis will provide recommendations for later implementation in variety value testing in order to be able to carry out a meaningful evaluation in a cost-efficient manner. Modern methods for assessing drought resistance within variety value testing make an important contribution to climate change adaptation and sustainability in relation to the new Seed Regulation. In addition, Austrian agriculture will be made fit for the future, which will also improve food security and competitiveness.