Investigation of improving salinity stress damages in Diospyros lotus seedlings by putrescine and chitosan

Salinity is one of the most important plant growth limiting factors, which using the anti-stress materials is considered as an important approach in moderating its effects on plants. In this research, the date plum seedlings response to salinity stress and two compounds putrescine and chitosan to reduce salinity stress was studied. The experiment was conducted as a factorial with three levels of sodium chloride (0, 30 and 60 mM), and five treatments of control, putrescine (1 and 2 mM) and chitosan (0.25 and 0.5 %), based on a completely randomized design with four replications at Shahed university in 2016. The results showed that date plum was sensitive to salt stress in the early stages of growth and sodium chloride salinity stress resulted in significant decrease in vegetative traits such as fresh matter weight and length of shoots and roots as well as leaf chlorophyll content in compared to 0 salinity. In addition, the leaf blight percentage, sodium content, electrolyte leakage and malondialdehyde content were increased in plants treated with salinity. Putrescine treatment, especially at 2 mM concentration effectively reduced the effects of salinity on date plum seedlings and improved vegetative growth of stem and root, while chitosan had no significant effect in reducing the harmful effects induced by salt stress in this experiment. According to the results, Diospyros lotus seedlings were sensitive to salinity and using treatments such as putrescine is effective in increasing its resistance to salinity stress.