Asian Journal of Plant and Soil Sciences

Soil salinity poses a critical threat to global food security, with tomato being particularly vulnerable during its early growth stages. This study was conducted at the Crop Production Laboratory of the Federal University of Technology, Minna, to evaluate the differential responses of five tomato genotypes (NHTO-0355, NHTO-0340, NHTO-0206, NHTO-0240, and NHTO-0238) to varying levels of sodium chloride (0, 20, 40, 60, and 80 mM) stress and to identify potential salt-tolerant genotypes for use in saline-prone environments. The experiment was laid out in a completely randomised design with a 5 x 5 factorial arrangement. Data were collected on germination and seedling growth parameters. The results revealed highly significant (p<0.05) main and interaction effects for all traits, underscoring the strong genotypic dependence of salinity response. Among the genotypes, NHTO-0206 consistently outperformed its counterparts, demonstrating remarkable resilience by maintaining the highest germination rates, the most rapid germination speed, and the greatest seedling vigour across all salinity treatments, even at the highest stress level of 80 mM NaCl. In contrast, genotype NHTO-0355 exhibited extreme susceptibility, with near-total inhibition of germination and growth under stress. Interestingly, while high salinity (80 mM) universally suppressed most traits, moderate stress levels (20–60 mM) exhibited a nuanced effect, with some genotypes showing a relative stimulation of radicle elongation, suggesting an adaptive osmotic adjustment mechanism. The study concludes that significant genetic variability exists for salinity tolerance in tomato and robustly identifies NHTO-0206 as a promising candidate for direct cultivation or as a genetic resource for breeding programmes aimed at enhancing resilience to salt stress. These findings provide a foundational basis for selecting and developing salt-adapted tomato varieties to sustain productivity in increasingly salinised agricultural systems.