تاثير متابوليت هاي سازگاري بر روابط آبي ارقام يونجه در سطوح مختلف شوري

Effects of Adaptive Metabolites on Water Relations of Alfalfa Cultivars at Different Salinity Levels

There is a specific relation between accumulation of some organic micro molecules, which plays a role in cell osmotic regulation, and salinity tolerance in saline induced plants. To evaluate accumulation of some compounds on water relations of alfalfa cultivars, an experiment was conducted in factorial design. arranged in RCBD with 3 replicates and 5 salinity levels (0 as control, 50,100, 150 and 200 mM NaCl) in greenhouse. Four alfalfa varieties (Sistan and Bluchestan, Golestan (20313), FAO (2566) and Hamedani Ahar) were irrigated with Hougland nutrient solution in hydroponics culture. Salinity stress reduced plant water potential and tissues relative water content (RWC). Reduction in RWC was proportional to reduction in water potential under saline condition. Least and most reduction of RWC and water potential were observed in "Golestan" and "Hamcdan-Ahar; respectively. Results showed that major reason lot- reduction of water potential of varieties under saline condition was due to accumulation of adaptability metabolites especially soluble carbohydrates. The correlation between adaptability metabolites with RWC was significantly positive hut with water potential was negative Significant differences were observed for all traits. The most accumulation rate of proline and solo ʹcarbohydrates concentrations were in Sistan and Baluchestan and Golestan (20313). and the least were in FAO (2566) and Hamedani Ahar. Stomata! resistance has a role on adaptive metabolites on water relations in Alfalfa because resistant varieties with the least stomata! resistance provided more energy for adaptive metabolites production.