The effects of NaCl concentrations (0 mM, 40 mM, 80 mM, and 120 mM) on soybean growth, physiology, and biochemical were investigated. Increasing salinity decreased plant height, root length, leaf number, leaf greenness, biomass, and chlorophyll content, while proline levels increased. There were significant interactions between cultivars and NaCl concentrations in almost all parameters. At 120 mM, plant death was found in Chiang Mai 84-2 and Chiang Mai 60 cultivars, in contrast, the cultivar Nakhon Sawan 1 exhibited no plant death at any NaCl concentration, indicating its suitability for salinity stress.
