Effect of Silicon on the Photosynthesis Rate and Nutrient Concentration of Strawberry Grown Under Saline Conditions

Salinity is recently regarded as the major abiotic stress for plant and new studies show that Si plays an important role in plant resistance to environmental stresses such as salinity. An experiment was conducted to study the effect of Si and NaCl salinity on the growth, yield and fruit quality of strawberry (Fragaria × ananassa Duch) cvs “Selva” grown hydroponically in the controlled glasshouse. Three levels of NaCl (0, 20, 40 mM) and three levels of Si (0, 1, 2 mM) was factorially combined in a completely randomized design with four replicates. The photosynthesis rate was measured in the flowering stage. At the end of the experiment, the plants were totally removed and biochemical properties such as nutrient concentration, proline content and electrolyte leakage were measured. The results showed that increasing the NaCl Levels, increased the proline content and electrolyte leakage, but reduced the photosynthesis rate. Silicon treatments improved photosynthesis rate and reduced the proline content and electrolyte leakage. In the saline conditions, concentration of N, NO-3, K and K/Na ratio were reduced, however, concentration of Na and Cl- increased. Increasing the silicon in the saline condition, reduced concentration of Na and Cl- in the leaf tissue. Concentration of N, NO-3, K and K/Na were increased by silicon application. Concentration of P was not affected by the treatments. The results showed that, the concentration of Si in plant was increased by Si addition into the nutrient solution, but was reduced in the saline condition. Based on the results of this study the application of Si in a concentration of 1mM could be recommended for salinity stress conditions.