Vegetos

Abstract

Potassium or silicon could enhance salt tolerance of plants. However there is little information about the combined effects of these two elements on plants under stress. Effects of KNO₃, K₂SiO₃ with K⁺ removal or K₂SiO₃ on NaCl tolerance of Poa pratensis were compared. Leaf gas exchange, osmotic adjustment substances, anti-oxidative enzyme activities and biomass were compared between different treatments. It showed that the addition of KNO₃ or K₂SiO₃ could alleviate salt stress by promoting growth; reducing intracellular proline, soluble protein and soluble sugar; increasing chlorophyll content, photosynthetic rate, water use efficiency and antioxidative enzyme activities. K₂SiO₃ had a better mitigation than KNO₃ when the K⁺ concentration was the same. At the same Si concentration, the mitigating effect of K₂SiO₃ was not significantly different from that of K₂SiO₃ with removal of K⁺. The results indicated that there was no synergistic effect between Si and K.