Effects of salt stress on germination characteristics of Agropyron mongolicum and salttolerance evaluation

The germination characteristics of 7 wild ecotypes of Agropyron mongolicum from different areas and cultivar Mengnong No. 1 under different NaCl concentrations（0.00%, 0.30%, 0.60%, 0.90%, 1.20%）were measured and salt tolerance performances were comprehensive evaluated by membership function. The result showed the salt stress had obvious inhibition on each index because the germination percentage, germination potential, germination index, vitality index and relative seedling length and root length obviously decreased with the increase of salt stress. Light salt stress (0.30% and 0.60%) promoted radicle growth for some materials and heavy salt stress (0.90% and 1.20%) strongly inhibited radicle growth for all these 8 germplasms. Based on the membership function method, the salt stress tolerance of these studied 8 germplasms decreased in the following order: Fengjigou No.7 Xinzhuangji No.5 Maerzhuang No.4 Yehujing No.3 Sidunzi No.1 Sidunzi No.2 Agropyron mongolicum cv. Mengnong No.1 Luoshan protection No.6. Thus, the germplasms from Fengjigou had stronger salt tolerance and the germplasms from Luoshan natural reservation had weaker tolerance.