Abstract: In order to compare the usefulness of ISSRs and SSRs in Elymus species, 33 ISSR primers and 137 wheat SSR primer pairs were employed to detect 12 species of Elymus in this study. The results indicated that 18 ISSR primers and 14 wheat SSR primer pairs were available to analysis genetic diversity of Elymus species. PCR analysis for 12 species showed that both ISSR and SSR markers appear high polymorphism, whose percentage of polymorphic bands were 84% and 91%, respectively. The results of cluster analysis based on ISSR and SSR markers were coincided highly with ploidy level and morphologic taxonomy. For 12 species, ISSRs (10.2) got a MI (marker index) value 1.4 folds higher than that of SSRs (4.3), whilst SSRs had a higher MI than that of ISSRs for 4 near related species, E. excelsus, E. cylindricus, E. tangutorum and E. dahuricus. Mantel test revealed that the relation of genetic similarity matrix between ISSRs and SSRs was significant (r=0.856, t=6.446) for 12 species, but not significant (r=0.679, t= 1.595) for 4 near related species. The variance of maker utility and relateness between the two types of markers at different consanguinity levels showed different effective diversity detection scopes of ISSRs and SSRs.

Key words: Elymus, ISSR, SSR, Genetic diversity