Evaluation of salt-tolerant genotypes of two processing tomato derived from in vitro regeneration under salt stress

Performance of salt-tolerant selected genotypes of two processing tomato varieties (Lycopersicon esculentum Mill.), Riogrande and Chibli F1, derived from in vitro regeneration under salt stress (34 mM), was evaluated under greenhouse conditions. This study was conducted with salinized solution culture at 10 mM (control) and 44 mM NaCl (concentration). The following parameters were recorded: plant height, plant dry weight, number of tomato fruits/plant, fruit weight and size, fruit yield/plant and fruit quality. Results showed that salt-tolerant plants of both varieties produced fruits with a better quality. There was an increase of total soluble solids content (+47% Chibli F1 and +33% Riogrande, regarding control), fruit firmness (+33% Chibli F1 and +25% Riogrande) and a decrease of fruit juice pH. However, this increase in fruit quality was associated with a decrease in fruit size (-15% Chibli F1 and -20% Riogrande) and weight (-16% Chibli F1 and -19% Riogrande). Nevertheless, a significant increase in fruit yield was observed (+30% Chibli F1 and +20% Riogrande). These findings show also a better salt tolerance of Chibli F1 regenerated plants and they may be useful for exploitation of saline water (34 to 50 mM of NaCl) of Sahel regions in Tunisia.