Mitigating Osmotic Drought Stress in Rye: Assessing the Ameliorative Effects of Putrecine on Germination, Seedling and Mitotic Index

Abstract In this study, the impact of putrescine, a polyamine, on the germination, seedling growth, and mitotic index of rye seeds (cv. Aslım-95) was investigated under osmotic drought conditions induced by polyethylene glycol (PEG-6000) application. The experiment involved six different PEG doses (-2, -4, -6, -8, and -10 bars) in combination with putrescine doses of 0.001, 0.01, and 0.1 mM. The concentration of -2 bars of polyethylene glycol, representing osmotic drought, positively influenced some of the studied characteristics. However, the stimulative effect of -2 bars of osmotic drought exhibited minimal changes with PEG 6000 + putrescine combinations. Conversely, as the osmotic drought level (PEG 6000 concentration) increased beyond that concentration, all the observed characteristics were negatively impacted. All putrescine doses used in combination with PEG 6000 demonstrated positive effects on the examined characteristics and reduced the germination duration. The most significant effect of putrescine was observed at a concentration of 0.1 mM on the base dry weight and 0.001 mM concentration on all other characteristics. Consequently, high doses of osmotic drought stress, particularly, adversely affected germination and seedling growth. It was determined that all putrescine doses could partially alleviate the negative effects induced by osmotic drought caused by PEG 6000.