Abstract:Soil salinization and alkalization reduce the usability of arable land and impair crop production. Identifying and selecting maize germplasm showing salt-tolerant is of significant importance in the reclamation and utilization of saline-alkali land. To determine the optimal NaCl concentration for screening salt tolerance in maize seedlings, 16 representative inbred lines were treated with 0 (control), 100, 150, 200, 250, and 300 mmol/L NaCl solutions for seven days. Six indicators, including shoot height, root length, shoot fresh weight, root fresh weight, shoot dry weight and root dry weight, were measured, along with recording the seedling conditions. The results showed that after seven days of salt treatment, significant differences were observed in all indices under 150 mmol/L compared with the control, and the coefficient of variation was greater than at other salt concentrations. Therefore, 150 mmol/L was identified as the optimal concentration for salt tolerance identification in maize inbred lines, and a salt tolerance identification technology was developed. Using this technology, 76 maize inbred lines were analyzed, and a comprehensive salt tolerance evaluation index (D) was calculated using the weighted subordinate function method and cluster analysis. The 76 lines were categorized into four groups: high salt tolerance, salt tolerance, salt sensitivity, and high salt susceptibility. Among them, the inbred lines Ming71, Zhong106, Si-287, and 8112 showed the strongest salt tolerance, serving as valuable resources for salt tolerance maize breeding. The salt tolerance coefficient of the fresh weight of the above-ground tissues showed the highest correction with the D value and could be used as the primary indicator for evaluating salt tolerance in maize inbred lines during the seedling stage.