[Genetic diversity of gliadin in wild germplasm of Elymus nutans Griseb]

Acid polyacrylamide gel electrophoresis (A-PAGE) was used to detect the gliadin genetic polymorphism among thirty-three wild accessions of Elymus nutans Griseb collected from four provinces and regions in China (Xinjiang, Qinghai, Sichuan and Tibet). The follows results were obtained. (1) A total of 38 bands were detected in all accessions, 92.1% were polymorphic bands. The average number of Shannon index to four electrophoretic zones was 0.55. The Nei's genetic similarity coefficient of the tested accessions ranged from 0.36 to 0.94, and the average Nei's coefficient was 0.63. These results suggested that there was rich genetic polymorphism among the tested wild resources of Elymus nutans Griseb. (2) 33 wild accessions can be clustered into seven groups at GS = 0.67 level on dendrogram. The principal coordinates (PCA) reflected almost the same relationships among the studied materials as shown in cluster analysis. Moreover, the groups 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 between and within five eco-geographical groups of Elymus nutans was estimated by Shannon's diversity index, which shown that 42.94% genetic variance existed within group, and 50.76% genetic variance was among groups. This result might be correlative to mainly self-pollinated breeding system of E. nutans. (4) UPGMA cluster analysis based on Nei's unbiased measures of genetic identity was assayed for five geographical groups of Elymus nutans, indicating that there was a significantly positive correlation between genetic differentiation and geographical habits among the five groups.