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土壤盐碱胁迫是限制作物生产力的世界性问题。很多研究关注盐分胁迫或者碱胁迫单因子对作物的影响,盐碱混合胁迫的研究较少。本研究按照研究区自然土壤盐碱主要成分和组成比例(NaCl、Na2SO4、Na2CO3质量混合比例为1∶0.5∶0.5),设置了不同浓度的盐碱处理(0,100,200,400 mmol/L),模拟无胁迫、轻度胁迫、中度胁迫和重度胁迫。试验材料为2个葡萄品种克瑞生和摩尔多瓦的3年生实生苗。研究结果表明,轻度盐碱处理能在一定程度上改善2个品种的光合能力。高浓度盐碱胁迫条件下,两品种的净光合速率和气孔导度数值均比对照提高,光合-光响应曲线趋势表现一致。对于克瑞生,光合速率的提高得益于气孔导度和蒸腾速率的提高,但是较低的PSⅡ光化学效率降低了这种惠益。对于摩尔多瓦,较高的PSⅡ光化学效率帮助了其保持较为稳定的净光合速率。2个品种显示了对盐碱胁迫的不同适应性机制。
Soil salinity-alkali stress is a worldwide problem that limits crop productivity. Many researches pay attention to the effect of single factor of salt stress or alkali stress on crops, and few studies on saline-alkali mixed stress. In this study, salt and alkali treatments (0, 100, 200, and 400 mmol / L) were set up according to the main composition and composition ratio of natural saline soil and alkali in the study area (1: 0.5: 0.5 NaCl, Mild stress, moderate stress and severe stress. The test material is a three-year-old seedling of two grape varieties, Crane Health and Moldova. The results showed that mild saline treatment could improve the photosynthetic capacity of two cultivars to a certain extent. Under high salt and alkali stress conditions, the net photosynthetic rate and stomatal conductance of both cultivars were higher than that of the control, and the trend of photosynthesis - light response curve was consistent. For Creosone, the increase in photosynthetic rate is due to an increase in stomatal conductance and transpiration rate, but lower PSII photochemical efficiency reduces this benefit. For Moldova, the higher photochemical efficiency of PSII helped maintain a more stable net photosynthetic rate. Two varieties showed different adaptation mechanisms to saline-alkali stress.