• stress response
• tomato
• Moneymaker
• Ciettaicale
• salinity stress
• Solanum pimpinellifolium

Human activities and global climate change have accelerated water resource degradation, impacting both quantity and quality, particularly in arid regions like the Mediterranean. Thus, developing salt-tolerant cultivars is vital for future food security. This thesis analyzes salt stress responses in three tomato genotypes (Moneymaker, the Ciettaicale landrace, and the wild ancestor Solanum pimpinellifolium) to identify resistance traits for future breeding. Plants were greenhouse-cultivated and exposed to increasing NaCl concentrations (120, 240, 360 mM) in nutrient solutions for one week, followed by a recovery week in a NaCl-free nutrient solution. Morpho-physiological parameters of the epigeal portion were assessed, including fresh and dry weight, cations, PSII efficiency, relative water content, leaf water potential, sugars and photosynthetic pigments. Significant differences were evaluated with statistical analysis via ANOVA and Kruskal-Wallis test. Ciettaicale displayed promising responses, maintaining its biomass and low sodium levels up to 120 mM NaCl. It also kept manganese levels unaltered up to 240 mM NaCl and showed superior chlorophyll recovery to S. pimpinellifolium. The latter maintained the same potassium levels and the lowest stomatal conductance but showed a drop in sugars under 360 mM NaCl. In conclusion, S. pimpinellifolium and Ciettaicale exhibit interesting salinity resistance traits, valuable for future studies aimed at the genetic improvement of tomato varieties.