Salinity effects on growth and carbon balance in Lycopersicon esculentum and L. pennellii

The effects of salinity on growth and carbon balance in the cultivated tomato Lycopersicon esculentum (L.) Mill. cv. VF 234 and in a wild, salt-tolerant relative, L. pennellii (Correll) D'Arcy accession Atico, were compared. The level of salinity that significantly reduced growth and affected morphology was lower for the cultivated than for the wild species.
Net CO₂ fixation, stomatal conductance and the specific activity of ribulose bisphosphate carboxylase (EC 4.1.1.39) were more decreased by salinity in the wild tomato than in the cultivated. In both species, the salinity-associated decrease in assimilation was related to a decrease in net photosynthesis and to carbon reallocation favoring heterotrophic organs.