مرکز منطقه ای اطلاع رساني علوم و فناوري - Evaluation of the Salinity Effects on Some Physiological and Biochemical Characteristics of Two Wheat Cultivars

Abstract :

Salinity is one of the most important abiotic stresses reducing wheat yield in most parts of the world. This study was conducted to evaluate the response of two wheat cultivars namely; ‘Karkheh’ (salt sensitive) and ‘Golestan’ (salt tolerant) to salinity stress grown in hydroponic system. The seedlings with 4-5 leafs were incubated under two conditions; lack of salinity (control) and salinity (200 mM NaCl) for 14 days. The results showed significant increase for activities of antioxidant enzymes such as catalase (CAT), ascorbate peroxidase (APX) and guaiacol peroxidase (GPX) in ‘Golestan’ under salinity. Furthermore significant increase in CAT activity was found in ‘Karkheh’ under saline situations compared the control. Salt stress elevated the amounts of malondialdehyde (MDA) in both cultivars. However, the increasing rate in ‘Karkheh’ was more than (two times) that of ‘Golestan’. Moreover, unlike with ‘Karkheh’, membrane stability index was not affected by salinity in ‘Golestan’. Both cultivars displayed increasing trend in Na^+ content and Na^+/K^+ ratio. However, Na^+/K^+ ratio of ‘Golestan’ was greater than one due to salinity. Also, this cultivar obtained significantly higher amounts for soluble sugars content under salt stress compared to control. The studied parameters elucidated that salt resistance of ‘Golestan’ might be due to increased activity of antioxidant enzymes, low lipid peroxidation, assumingly minimum change in membrane stability index and more Na^+/K^+ ratio along with significant increase in soluble sugars and its probable ability to isolate Na^+ in vacuoles.