Salinity is a pressing and widespread abiotic stress, adversely affecting agriculture productivity and plant growth worldwide. Seed germination is the most critical stage to seedling growth and establishing plant species in harsh environments, including saline stress. However, seed germination characteristics and stress tolerance may vary among geographical locations, such as various provenances. Suaeda salsa (Linn.) Pall. (S. salsa) is a halophytic plant that exhibits high salt tolerance and is often considered a pioneer species for the restoration of grasslands. Understanding the germination characteristics and stress tolerance of the species could be helpful in the vegetation restoration of saline–alkali land. In this study, we collected S. salsa seeds from seven different saline–alkali habitats (S1–S7) in the Songnen Plain region to assess the germination and seedling growth responses to NaCl, Na₂CO_3, and NaHCO₃, and to observe the recovery of seed germination after relieving the salt stress. We observed significant differences in germination and seedling growth under three salt stresses and among seven provenances. Resistance to Na₂CO₃ and NaHCO₃ stress was considerably higher during seedling growth than seed germination, while the opposite responses were observed for NaCl resistance. Seeds from S1 and S7 showed the highest tolerance to all three salt stress treatments, while S6 exhibited the lowest tolerance. Seeds from S2 exhibited low germination under control conditions, while low NaCl concentration and pretreatment improved germination. Ungerminated seeds under high salt concentrations germinated after relieving the salt stress. Germination of ungerminated seeds after the abatement of salt stress is an important adaptation strategy for black S. salsa seeds. While seeds from most provenances regerminated under NaCl, under Na₂CO₃ and NaHCO₃, only seeds from S4 and S7 regerminated. These findings highlight the importance of soil salinity in the maternal environment for successful seed germination and seedling growth under various salinity-alkali stresses. Therefore, seed sources and provenance should be considered for vegetation restoration.

Soil salinity poses a significant challenge for global agriculture and ecosystems, severely impacting plant growth and land-use efficiency. Leymus chinensis (L. chinensis) is a perennial grass with a high potential for saline soil restoration, yet little is known about whether its salt tolerance during germination aligns with that during seedling development, which are considered the most salt-sensitive stages of its life cycle. Therefore, to investigate whether there is a correlation between salt tolerance during germination and the seedling stage, we evaluated the germination, growth, and survival of 10 genotypes of (G1–G10) L. chinensis under 0, 50, 100, and 150 mM NaCl stress over 12 weeks. Key indicators, including germination traits (germination percentage, radicle length, and shoot length), plant height, and survival rate, were integrated into stage-specific Comprehensive Evaluation Values (D value) to quantify salt tolerance. Salt stress significantly suppressed germination and seedling performance, with inter-genotypic variation. For example, G3 showed only an 18.0% reduction in germination percentage and 62.5% survival rate at 150 mM NaCl, while other genotypes had a 42.0–88.0% germination loss and over 90.0% mortality. However, a correlation analysis showed a positive yet non-significant correlation between D-Germination and D-Survival. Notably, D-Plant Height was negatively correlated with both D-Germination and D-Survival, with G3 and G8 displaying contrasting stress adaptation strategies. Collectively, these results indicate that salt tolerance in L. chinensis is both stage-specific and genotype-specific and that performance at germination does not reliably predict later survival. The findings of this study provide valuable germplasm resources and a theoretical basis for forage breeding and grassland restoration. The identified genotypes, G3 and G8, can serve as important materials for research on salt tolerance mechanisms and breeding programs.