The effect of silicon applications on seedling growth stress parameters in lettuce (Lactuca sativa L.) under salt stress conditions

Salt stress prevents plant growth and development by disrupting osmotic and ionic balance. Inthisstudy; As a result of silicon (Si) application, which can activate tolerance mechanism sagainst salt stress in lettuce seedlings; Changes in antioxidant (SOD, CAT, APX, POD) and physiological parameters (proline, leaf chlorophyllratio, leaf membrane permeability and relative water content) effective on seedling growth were investigated. Control plants grew beter than plants treated with only salt. As a result of Si+100 mM NaCl and Si+50 mM NaCl applications; Increases between 176% and 339% in SOD, CAT, APX, POD levels, increases between 26.9% and 28.1% in leaf chlorophyll and moisture content and decreases between 15.2% and 76.4% in leaf membrane damage were determined. The relationship between proline accumulation and antioxidant enzyme activities was effective with Si application and showed that plants improved their defense against salt stress. Plant development decreased according to the severity of salt as a result of only salt applications. Itwasdeterminedthat I50x100kg.ha-1Si interaction was moreeffective on plantgrowth in allplots.