Germplasm resources and drought resistance evaluation of Siberian wildrye ( Elymus sibiricus L.) in the Tibetan Plateau

Siberian wildrye ( Elymus sibiricus L.) is an important ecological forage in the plateau region of the world. Drought stress is one of the main environmental factors limiting the yield of Siberian wildrye. Accordingly, it is of great significance to select and breed Siberian wildrye which is suitable for growing in the arid environment in the plateau area. In this study, 11 germplasm resources of Siberian wildrye collected in the Tibetan Plateau were used to analyze their production performance and nutritional quality and comprehensively understand the physiological response of Siberian wildrye under four drought stress conditions (30%, 45%, 60% and 75% of the field water holding capacity). The results showed that there were significant differences in production performance and nutritional quality among different germplasms of Siberian wildrye. Drought stress increased the contents of malondialdehyde, superoxide dismutase and proline, but decreased the relative survival rate. The comprehensive analysis of grey correlation and membership function showed that 18–211, 16–118, 16–262 and ‘Qingmu No. 1’ could be regarded as the representatives of excellent germplasm resources of Siberian wildrye. The evaluation of germplasm resources and the analysis of drought resistance can promote the breeding and improvement of drought resistant varieties and provide basic data for the promotion excellent ecological pasture in another plateau.