Determination of the effects of different putrescine and salicylic acid applications on germination, plant growth, quality properties and nutrient content of lettuce (Lactuca sativa L.) under saline conditions

This study was conducted to determine the effects of putrescine and salicylic acid applications at different doses on germination, plant growth, quality properties and nutrient contents in lettuce under saline conditions. In the study, a total of 16 different applications using 2 different levels of salt (100 and 200 mM), 2 different doses of putrescine (0.5 and 1.0 mM) and 2 different doses of salicylic acid (0.5 and 1.0 mM) were investigated. The effects of putrescine and salicylic acid separately and together with salt were examined. According to the findings obtained from the research, it was detected that salinity negatively affected the germination, plant growth, quality properties and nutrient contents of lettuce. In general, it was determined that putrescine applications increased germination and plant growth parameters under saline conditions and significantly reduced the negative effects of salt stress. It was detected that application number 11 (1 mM Putrescine + 200 mM NaCl) in which salt and putrescine were used together increased germination rate by 75.57%, plant height by 42.49%, plant fresh weight by 58.89% and number of marketable leaves by 43.20% compared to application number 3 (200 mM NaCl). Among the applications examined in the study, it was concluded that the applications in which salt and putrescine are used together are the most effective applications against salt stress in lettuce and can be recommended as an alternative application method for lettuce cultivation in areas with salinity problems.