Potential Antioxidant Activities Improve Salt Tolerance in Ten Varieties of Wheat (Triticum aestivum L.)

摘要

The activity of antioxidative enzymes system is affected by salt stress, chlorophyll content (CHL), leaf relative water content (RWC), Na+ and K+ contents, their ratio and some oxidative stress indices were studied in leaves of ten bread wheat cultivarsSehar-06, Lu-26, NARC-09, BARC-09 and Pirsbak-09’(salt-tolerant) and Kaghan-94, Rohtas-90, Soughat-90, Shaheen-94 and Zardana-89’(salt-sensitive), grown under salinity treatments carried out in five levels (1 dS·m-1 as control, 2, 4, 8, 16 dS·m-1) via sodium chloride. Under high salt potency significant increase for activities of antioxidant enzymes such as ascorbate peroxidase (APX) and guiacol peroxidase (GPX), occured in salt tolerant varieties. Meanwhile, under salinity condition the activities of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) and (GPX) in sensitive cultivar were lower than control. Regarding (APX) activity there was no significant difference between salinity and control situation. Under salt stress membrane stability index (MSI) of both cultivars were negatively influenced. Hydrogen peroxide (H2O2) content of salinity sensitive cultivars was higher than control. Salt tolerant varieties had more amounts of K+ content, K+ and Na+ ratio, relative water content, yield and chlorophyll under salt conditions, and sensitive ones recorded higher Na+ content at tillering stage. The mechanism of salt stress might be achieved due to low lipid peroxidation, assumingly lower changes in membrane stability index and evasion of Na+ combination and amplified activity of antioxidant enzymes.