*4.9. Growth Conditions and Evaluation of Salinity Tolerance at Seedling Stage*

We evaluated "YNU31-2-4" and the parents for seedling-stage salt tolerance in the growth chamber at 26/23 ◦C (12/12 h) and a relative humidity of 70%. Pre-germinated seeds were placed in 230-mL plastic pots filled with rice nursery culture soil containing 0.5 g N, 0.9 g P, and 0.5 g K/kg. The experiment consisted of four treatments: 0 (control), 50, 75, and 125 mM NaCl (pH 5) The salt stress was imposed ten days after germination. The experiment used four biological replicates, each with 10 seedlings. Phenotype was evaluated 2 weeks after salt was imposed.
