Identification of four Elymus sibiricus cultivar (strains) from Northwest Plateau of Sichuan using morphological traits and SSR markers

Based on 23 morphological traits and SSR markers, three cultivars (Chuancao No. 2, Aba and Kangba) and a new strain (Yajiang) of Elymus sibiricus widely utilized in Northwest Plateau of Sichuan were identified. There was obvious difference among varieties at phenotypic traits and genetic background. Morphological traits were measured, includingplant height, leaf length, leaf width, Culm diameter and so on, the new strain ‘Yajiang’ had betterperformance in major agronomictraits than that of other three varieties (P<0.05). Furthermore, 13 screened pairs of SSR primerwere amplified in four cultivars (strains) and generated 90 bands, of which 68 bands were polymorphic. According to the mean of percentage of polymorphic bands (PPB=76.32%), polymorphism information content (PIC=0.309) and Shannon diversity index (H=0.451), four cultivars (strains) presented high polymorphism. A positive correlation (r=0.696, P=0.08) existed between Euclidean distance and Dice genetic distance, indicating that the combination of morphological traits and genetic markers could be used for cultivar identification. Two UPGMA dendrogram based on morphological and SSR data were similar and there were differences among all cultivars (strains) for phenotypic and genetic background. Furthermore, four pairs of primers (Elw0669s043, Xgwm190, WMS169 and Xgwm311) were selected for DNA fingerprinting construction and cultivar identification. In general, the present study demonstrated that the new strain ‘Yajiang’ was significantly different from other three E. sibiricus cultivars, and provided important data for genetic relationship analysis and intellectual property rights protection for cultivars in the Northwest Plateau of Sichuan.