Physiological and agronomic evaluation of Camelina sativa (L.) Crantz for oil production on salt-affected soils

Soil salinization increasingly constrains agricultural productivity in Mediterranean regions, where saline-sodic conditions interact with drought and heat to generate seasonal salinity peaks. In these environments, crop diversification with resilient, low-input species is essential for climate adaptation. Camelina sativa (L.) Crantz, a short-cycle Brassicaceae oilseed crop, shows potential for marginal lands, yet its tolerance to salinity across the full crop cycle remains unexplored. This thesis investigates camelina responses to salinity through controlled-environment experiments and field validation, aiming to define predictive selection criteria and management strategies for salt-affected Mediterranean soils. A germination and seedling assay revealed significant intraspecific variation and identified 200 mM NaCl as a critical threshold for reduced germination. Screening of 58 lines resolved three functional clusters differing in germination dynamics and early vigor under salinity. Representative lines were evaluated in pots on field-derived saline-sodic soils. Clusters 1 and 2 lines maintained seed yield under moderate salinity (ECe 4.5 dS m⁻¹), whereas Cluster 3 line exhibited early yield collapse. Yield stability was associated with osmotic adjustment and maintenance of reproductive sinks rather than vegetative growth or photosynthesis. Two-year on farm field trials in northeastern Italy confirmed these patterns: Cluster 1 lines achieved a seed yield of about 1.2 t ha⁻¹ at a coastal saline site, comparable to yields at a nearby non-saline inland site. Linear modelling showed that yield was driven mainly by salinity increases after flowering rather than by average salinity. Complementary experiments showed that alkaline salinity induced stronger membrane depolarization and ionic imbalance than neutral salts, limiting stress recovery. Pot and field results indicated that genotypes showing delayed germination exhibited greater tolerance, whereas rapid germination predicted later sensitivity. Overall, camelina represents a viable diversification crop for moderately salt-affected Mediterranean systems, although alkaline salinity remains a major constraint.