To identify salt-tolerant germplasm resources of Agropyron cristatum， this study subjected 31 germplasm samples to salt stress treatment with a soil salt content of 0.9%. Chlorophyll fluorescence parameters （phi2， NPQt， qL， Fv/Fm， Fo， Fm， Y（NPQ）， Y（NO）， and Y（II）） and physiological indicators （MDA， Pro， SS， and POD） were determined， and their salt tolerance was comprehensively evaluated using correlation analysis， principal component analysis （PCA）， and cluster analysis. The results showed that the coefficient of variation of the measured indicators of 31 samples ranged from 0.03 to 0.99. PCA indicated that the contribution rates of the top four principal components were 43.152%， 22.847%， 9.746%， and 8.882%， respectively. Cluster analysis suggested that the first group had higher photosynthetic efficiency and POD activity， and lower MDA content； the second group had moderate photosynthetic rate； the photosynthesis and physiological indices of the third group were severely affected. Based on PCA and cluster analysis， combined with changes in physiological responses， six salt-tolerant Agropyron germplasm （20-02， 20-03， 20-06， 20-08， 20-11， 20-17） were screened， most of which belonged to A. latissimum. In conclusion， the salt-tolerant germplasm obtained in this study could be used as the candidate materials for the breeding of new varieties of Agropyron， and also provide germplasm resources for the exploration of excellent salt-tolerant genes.

Agropyron cristatum  /  Salt tolerance  /  ChlorophyII fluorescence parameters  /  Physiological index