| In order to explore the physiological response characteristics of Lycium nigrofructus to wind-sand stress in the desertification area of northwest China, this study took Lycium nigrofructus in Qingtuhu District of Minqin, Gansu Province as materials, simulated natural wind-sand environment through net wind stress and wind-sand flow stress tests, measured physiological indexes such as photosynthesis, antioxidant enzymes and osmotic regulatory substances, and analyzed the data. The experimental data showed that Pn, Gs, Ci and Tr all increased first and then decreased with the increase of stress time under net wind stress. When the wind speed was 12 m/s, the Pn value was the highest, about 38.3 μmol·m-2·s-1. Under the stress of wind-sand flow, the above photosynthetic physiological indexes increased with the increase of stress time. In terms of antioxidant enzyme activity, the SOD activity was the highest at 5 m/s wind speed, while the POD activity was the highest at 8 min. The accumulation of osmotic regulatory substances showed that the highest proline content was found at 12 m/s wind speed, and the proline content increased significantly at 16 min. In terms of membrane lipid peroxidation degree, MDA content increased first and then decreased under the stress of clean wind and sand flow. Among the physiological indexes of water, the relative water content at 8m/s wind speed is the highest, reaching 90.3%. The results showed that the photosynthetic physiology and antioxidant enzyme activity of Lycium nigricum were significantly affected by the stress of wind and sand flow. Under different stress conditions, Pn was positively correlated with Gs and Tr, antioxidant enzymes and proline were synergistic to resist oxidative damage, and there was a trade-off between stomatal size and density. These changes reflected the adaptation mechanism of Lycium nigrofructus to wind and sand stress. |