Saline-alkali land is widely distributed worldwide， and it is of great significance to screen for germplasm resources of saline-alkali resistant Bromus inermis for improving saline-alkali land In this study 100 Bromus inermis germplasm resources were selected as the reseat objects. During the seedling stage， 200 mmol·L^-1 NaHCO₃ solution was used for stress treatment， and 14 traits including plant height， root length， seedling fresh weight/dry weight， root fresh weight/dry weight were measured. Multiple statistical methods such as correlation analysis， principal component analysis， membership function analysis， and cluster analysis were used to comprehensively evaluate the alkali tolerance of different smooth brome germplasm resources. The results showed that there were varying degrees of variation in the alkali tolerance coefficients of 14 personality traits， ranging from 39.52% to 74.83%. Relative conductivity was negatively correlated with 13 indicators including plant height， root length， and seedling fresh weight. Using principal component analysis， 14 traits were classified into 3 components， with a cumulative contribution rate of 73.719%. Plant height， stem thickness， fresh weight of aboveground parts， dry weight of aboveground parts， survival rate， root surface area， root volume， and relative conductivity can be used as the main evaluation indicators for alkali tolerance at the seedling stage of smooth brome. Cluster analysis grouped 100 rootless barley seeds into three categories， including 16 alkali tolerant materials， 63 medium resistant materials， and 22 alkali sensitive materials. The results provide excellent germplasm materials for the screening of alkali tolerance indicators and the breeding of new varieties of smooth brome.

Bromus inermis  /  Seedling stage  /  Alkali tolerance  /  Cluster analysis  /  Comprehensive evaluation