Effects of silicon on salinity tolerance of two barley cultivars

Abstract

Added silicon (Si) could significantly enhance dry matter yields of both salt‐sensitive (Hordeum vulgare L. Kepin No. 7) and salt‐tolerant (Hordeum vulgare L. Jian 4) barley cultivars under salt‐stressed condition. The dry matter yield of Kepin No.7 grown in the solution containing high Si (1.0 mM Si/L) and high salt (120 mM NaCl/L) was 18.0% greater than that of the plants treated with 120 mM NaCl/L alone. The dry matter yield of Jian 4 treated with low Si (0.5 mM Si/L) and high salt (120 mM NaCl/L) was found to increase by 15.2% compared with that of plants treated with 120 mM NaCl/L only. Silicon added could increase net photosynthetic rate of two barley cultivars grown in the solution containing 120 mM NaCl/L. The electrolytic leakage percentage was significantly lower in the leaves of two barley cultivars treated with 120 mM NaCl/L and 1.0 mM Si/L than in the leaves treated with 120 mM NaCl/L alone, which indicated that added Si resulted in a reduction of membrane permeability of salt‐stressed barley. Silicon could enhance the uptake of potassium (K) and inhibit the uptake of sodium (Na) by salt‐stressed barley, thus mitigating the toxicity of salt to barley and increasing salt tolerance of the plants.