Evaluation of osmotic stress tolerance during the germination stage in soybean genotypes

To evaluate the tolerance of soybean genotypes to osmotic stress, a controlled germination experiment was performed on six soybean lines: three obtained by gamma-ray-induced mutagenesis (C15M7200, B2M8200, Z21M12200) and three by hybridization (L.4, L.8, L.86). Seeds were treated with three concentrations of PEG 6000 (0%, 10%, 15%) to simulate a water stress gradient. The analyzed parameters - germination rate and root length - were recorded 5 and 7 days after sowing. A significant reduction of both parameters was found with increasing PEG concentration, highlighting a different sensitivity between genotypes. Lines C15M7200 and B2M8200 showed better tolerance, while L.8 and Z21M12200 were the most affected. The results highlight genetic variability and support the utility of PEG testing in the early stages of breeding programs for the selection of drought-tolerant genotypes.