ABIOTIC STRESSES’ RESPONSES AND GENETIC RESOURCES FOR CLIMATE ADAPTATION IN PERENNIAL CROPS

Given the environmental pressures currently faced by the Mediterranean basin, this study aimed to evaluate how perennial crop species respond to single and combined abiotic stresses and how genetic resources and adaptive traits could enhance resilience and climate adaptation. Among perennial crops, particular attention was given to the olive tree, a key plant of the Mediterranean region, deeply rooted in agroecological and cultural landscapes, and known for its resilience and tolerance to various abiotic stresses. It was complemented by hop, a crop more recently introduced into the local agricultural context and mainly cultivated for cone production, whose quality depends heavily on environmental conditions. The thesis examined in Chapter 1 and Chapter 2 the response to single abiotic stresses, respectively, drought on olive and salinity on hop. Both studies focus mainly on physiological responses, but for the hop, the biochemical compounds were also examined. In Chapter 3, a study on olive subjected to the combination of drought and heat is reported, using an approach that combined physiological traits with gene expression. To conclude, in Chapter 4, the thesis addresses olive germplasm, with particular focus on monumental trees, which are regarded as a significant repository of genetic diversity and a prospective source of adaptive traits relevant to resilience and climate adaptation. Collectively, these chapters offer an integrated framework for examining stress responses and the long-term adaptive capacity of perennial crops.