EFFECTS OF SILICON ON SALINITY TOLERANCE OF 2 BARLEY CULTIVARS

Added silicon (Si) could significantly enhance dry matter yields of bo th salt-sensitive (Hordeum vulgare L. Kepin No. 7) and salt-tolerant ( Hordeum vulgare L. Jian 4) barley cultivars under salt-stressed condit ion. The dry matter yield of Kepin No.7 grown in the solution containi ng high Si (1.0 mM Si/L) and high salt (120 mM NaCl/L) was 18.0% great er than that of the plants treated with 120 mM NaCl/L alone. The dry m atter 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 p lants treated with 120 mM NaCl/L only. Silicon added could increase ne t photosynthetic rate of two barley cultivars grown in the solution co ntaining 120 mM NaCl/L. The electrolytic leakage percentage was signif icantly lower in the leaves of two barley cultivars treated with 120 m M NaCl/L and 1.0 mM Sin, than in the leaves treated with 120 mM NaCl/L alone, which indicated that added Si resulted in a reduction of membr ane permeability of salt-stressed barley. Silicon could enhance the up take of potassium (K) and inhibit the uptake of sodium (Na) by salt-st ressed barley, thus mitigating the toxicity of salt to barley and incr easing salt tolerance of the plants.