Abstract：Acid polyacrylamide gel electrophoresis (A-PAGE) was employed to detect the gliadin genetic diversity among fifty-four wild accessions of Elymus sibiricus L. collected from Qinghai-Tibetan plateau. The follow results were obtained: (1) A total of 42 bands were detected in all accessions, of which 92.86% were polymorphic. The average number of Shannon index to four electrophoretic zones (α, β, γ, ω) was 0.4627. The Nei’s genetic similarity coefficient of the tested accessions ranged from 0.2424 to 0.9767, and the average Nei’s coefficient was 0.5822. These results suggested that there was a rich genetic polymorphism among the tested wild resources of E. sibirucus. (2) 54 wild accessions can be clustered into 4 groups at GS = 0.562 level on dendrogram. The principal coordinates (PCA) reflected almost the same relationships among the studied materials as showed in cluster analysis. Moreover, the accessions from the same origin frequently clustered into one group. The findings implied that a correlation among gliadin patterns, geographical and ecological environment. (3) Genetic differentiation of between and within five eco-geographical groups of E. sibiricus is estimated by Shannon’s diversity index, which shown that 68.17% genetic variance existed within group, and 31.83% genetic variance was among groups. (4) The unweighted pairwise groups method using arithmetic average (UPGMA) cluster analysis based on Nei's unbiased measures of genetic identity was assayed for five geographical groups of E. sibiricus, which indicated that there was a significantly positive correlation between genetic differentiation and geographical habits among the five groups.
