Combining metabolomics and phenotyping to discover biomarkers of resistance to downy mildew

Grapevine ( Vitis vinifera L. ) is one of the cultivated crops with higher socioeconomic impact in the world. Vitis vinifera cultivars frequently used for wine production are highly susceptible to fungal diseases, being downy mildew, caused by the oomycete Plasmopara viticola , one of the most destructive ones. The introgression of resistance traits by breeding is the most sustainable approach allowing a phytochemical free viticulture. Resistance to P. viticola in hybrid plants is achieved by crossing suitable parent lines or cultivars and the subsequent selection in the offspring to identify desired combinations of traits. At Julius Kuhn-Institut (JKI), one of the major grapevine breeding institutes in Europe, researchers are using sensor-based approaches (RGB, hyperspectral imaging) in the hybrid lines to complement infection-based leaf disc assay based on OIV descriptors. By adding FT-ICR based metabolomics, we aim at biomarker discovery, allowing the faster screening in breeding programs. To achieve this goal, leaf disc inoculations were conducted in different hybrids genotypes (carrying different resistance loci). Phenotype evaluation following the OIV descriptors was done and both hyperspectral imaging and metabolomic characterization are ongoing.