Evaluation of Salt Tolerance Mechanisms in Common Bean (Phaseolus vulgaris L.) Genotypes Exposed to Sodium Chloride and Sodium Sulfate: Morphological and Biochemical Perspectives

Background: Common bean is a nutritionally important crop, but increasing soil salinity threatens seedling establishment and productivity. Methods: This greenhouse pot study compared early-stage morphological and biochemical responses of two common bean genotypes (G3 and G13) exposed to two salt types (NaCl and Na2SO4) at two concentrations (20 and 40 mM), alongside a non-saline control. Plant height, biomass traits, leaf area, SPAD chlorophyll index, photosynthetic pigments (chlorophyll a, chlorophyll b, total chlorophyll, carotenoids), chlorophyll a/b ratio and proline were assessed. Result: Salt treatments influenced SPAD and pigment-related traits, whereas effects on growth traits and proline were smaller or less consistent under the tested conditions. Genotype-dependent differences were observed across multiple traits. Overall, pigment traits may be useful for early-stage screening of salt responses under controlled conditions; however, conclusions should be interpreted cautiously given the limited genotype set.