The Food and Agriculture Organization (FAO) declared 2020 as the international year of plant health and 2021 as the international year of fruits and vegetables. These initiatives aimed to raise awareness about the importance of healthy fruits and vegetables for human nutrition and a less polluted world.
Among fruit plants, grapevine cultivation is characterized by an intensive use of pesticide with consequent high human and environmental impacts. This is mainly due to the high susceptibility of cultivated grapes to powdery mildew (PM), which negatively affects yield and berry quality. Nevertheless, pesticides remain crucial in European agriculture as no effective alternatives are yet available for PM and other pathogens.
Plant breeding represents a valuable tool for obtaining genetic resources resistant to biotic stress. DEMETRA aims to dissect the genetic determinism of resistance/susceptibility to PM in grape through a multi-omics approach.
Two germplasm collections, FS-POP and GC-POP, will be employed in a marker-trait association analysis. FS-POP is a segregating population developed to assess the allelic segregation of PM resistance, while GC-POP is a collection of local varieties from Sicily and Campania, Italy's main wine-producing regions.
In the first year, both collections will be SNP-genotyped and phenotyped for PM resistance/susceptibility using established field protocols. The results will be integrated into a single-family QTL analysis and a genome-wide association study (GWAS).
In the second year, grapes with different QTL alleles and opposite phenotypes will be selected for in vitro fungal inoculation and sequencing of coding and small noncoding RNAs to understand the regulatory mechanism of stress response.
DEMETRA's results will provide insights into the defence mechanisms of cultivated grapes and the genetic and phenotypic variability of local varieties in southern Italy. Additionally, molecular markers linked to PM resistance/susceptibility will aid future breeding programs for selecting superior cultivars with lower environmental inputs.
