Effects of Exogenous Abscisic Acid on Photosynthesis of Lettuce under NaCl Stress

摘要

Soil salinization has become a global problem. This test used the method of spraying different concentrations (1, 5, 10, 20 μmol·L~(-1)) of ABA to lettuce leaves respectively, with spraying water as control, to discuss the effects of exogenous abscisic acid (ABA) on photosynthesis of lettuce under NaCl stress. The results showed that after spraying ABA, net photosynthetic rate (Pn), stomatal conductance (Gs), water use efficiency (WUE), light use efficiency (LUE), transpiration rate (Tr) and CO_2 concentration of intercellular (Ci) of lettuce have improved in varying degrees, and when the ABA concentration was 5μmol·L~(-1), enhanced by 33.67% (P <0.05), 24.38% (P <0.05), 7.47% (P <0.05), 33.67% (P <0.05), 56.66% (P <0.05) and 12.57% (P <0.05), respectively compared with CK. Therefore, spraying ABA can significantly improve photosynthetic capacity of lettuce leaves under NaCl stress, and the best results appear in 5 μmol·L~(-1).