Salinity tolerance in tomato genotypes at an early plant growth stage: Morphological and physiological responses

Salinity is a significant factor restricting plant development at various stages, resulting in lower yield and productivity. The current study was carried out to investigate and assess the tolerance of several tomato genotypes to salty conditions. Thirty (30) tomato genotypes were cultivated in pots and tested for salinity at three levels: 5 ds/m NaCl, 10 ds/m NaCl, and 15 ds/m NaCl, in comparison to the control (0 mM NaCl). Two weeks after treatment, several morphological and physiological parameters were measured. The effects of salt stress on tomato genotypes included a considerable reduction in leaf area, chlorophyll content, shoot and root length, shoot and root biomass, and relative water content. Different tomato genotypes responded differently to salinity severity score (SSS). Reduction of shoot dry weight (0.27 to 0.44) and leaf area (0.33 to 0.45) were positively correlated with SSS at moderate (10 ds/m) to higher (15 ds/m) salinity levels, respectively. Based on the experiment results, the genotypes BARI Tomato 4, BARI Tomato 14, BARI Tomato 15, SAU Tomato 2, AV0T0 1228, and NS 501 were found to be more salinity tolerant than other genotypes. The results showed that measuring shoot length, leaf area, and shoot fresh and dry weight was better for evaluating salinity stress and screening salt-tolerant tomato genotypes.