Physiological correspondence of four varieties of perennial ryegrass to drought stress

In order to study the drought resistance of different varieties of perennial ryegrass (Lolium perenne), four perennial ryegrass varieties were selected, and turf quality was determined by hydroponic experiment in the greenhouse using Macrogol 6000 (PEG-6000) to simulate drought stress. The physiological indexes of perennial ryegrass were determined, such as turf quality, aerial growth and root growth, water content, chlorophyll content and antioxidant enzyme activity. Results showed that after ten days of drought stress, the growth of the four perennial ryegrass varieties was obviously inhibited, and the water content of the four varieties was decreasing. In addition, the activity of antioxidant enzymes such as superoxide dismutase, peroxidase and catalase in the four varieties initially increased, and then decreased, and the content of malondialdehyde increased. Ranking of drought resistance was carried out using membership function analysis. The results indicated that the drought resistance of the four perennial ryegrass varieties ranked as: Pr521 > Vidas > Larking > Pr525.