Physiological response of six alpine grass varieties to drought stress and their drought resistance evaluation

Screening excellent drought resistant grass varieties is an important prerequisite for the rapid restoration of desertification grassland in alpine regions. In this study, six grass varieties mainly used in grassland restoration in alpine area were used as materials for pot experiment under drought stress, and the responses of shoot biomass, leaf moisture status, cell membrane permeability, chlorophyll content, superoxide dismutase and peroxidase activity of above varieties to drought stress were analyzed, the drought resistance of 6 grasses was evaluated comprehensively by subordinate function method. The results showed that drought stress inhibited the growth of six grasses, which showed that the leaf tissue water content and chlorophyll content decreased, the cell membrane permeability and the activity of antioxidant enzymes increased. Elymus sibiricus ‘Tongde’, E. sibiricus ‘Qingmu No. 1’ and E. breviaristatus ‘Tongde’ could maintain high antioxidant enzyme activities and grew better under drought stress. The order of drought resistance among 6 grasses was as follows: E. sibiricus ‘Qingmu No. 1’ > E. sibiricus ‘Tongde’ > E. breviaristatus ‘Tongde’ > Poa crymophila ‘Qinghai’ > Poa pratensis var. anceps ‘Qinghai’ > Festuca sinensis ‘Qinghai’. This study suggested that E. sibiricus ‘Qingmu No. 1’, E. breviaristatus ‘Tongde’, and E. sibiricus ‘Tongde’ were more suitable for planting in desertification grassland in alpine regions.