Effects of salt stress and supplemental silicon on morphological and ionic relations of rapeseed

The effects of salinity and complementary silicon on some morphological traits of canola, cv. Talaiie, an experiment was done in greenhouse. Treatments were four levels of potassium silicate (0, 1, 2 and 3mM) and four levels of chloride sodium (0, 0.3, 0.6 and 0.9 g/kg soil). In normal condition application of silicon had not a significant effect on measured traits. Salinity decreased leaf area, leaf and plant dry weight and leaf area ratio (LAR). Application of silicon to growth media enhanced mentioned traits. The highest morphological traits and biomass was found in mild salinity, 0.3 g NaCl, and all applied silicon levels. Salinity decreased LAR values which show salinity has strong effect on leaf expansion than biomass production. The highest specific leaf weight (SLW) found in highest salt level and non application of silicon. On the other hand, supplementary silicon reduced SLW in salt treatments, which show positive effects of silicon on leaf expansion. Sodium concentration increased with increasing salt levels in non-applied silicon treatments, but potassium and calcium concentrations were decreased. Application of silicon induced a reduction in sodium and potassium and calcium uptake compared to non-applied silicon treatments. The ratio of K/Na andCa/Na increased in all silicon treatments. Si concentrations in salted and normal condition were higher in silicon treated soils.