摘要：In order to assess the effect of salinity stress on growth traits and biochemical traits were mentioned. A factorial experiment was carried out with five alfalfa cultivars (Ardabil, Ghara-yonje, Miandoab, Tabriz and Sahand) and two salt stress levels induced by NaCl (0 and 200mM). Electrophoretic analyses were performed for superoxide dismutase (SOD), peroxidase (POX) and catalase (CAT) in leaves of alfalfa using 8% slab polyacrylamide gels. For, SOD, POX and CAT three, four and one isoforms were observed, respectively. On the basis of percent inhibition in growth traits at salinity stress cultivars Ghara-yonje was ranked as tolerant (percent inhibition less than 22%) and Miandoab salt sensitive (percent inhibition more than 40%). The applied salt stresses reduced dry weight, leaf weight, and stem weight and plant height about 38.9, 39.4, 36.3 and 38.7 percent, respectively. Salt stress, increased the activities of SOD, POX, CAT levels of total phenol-ics and malondialdehyde (MDA), and decreased the total soluble proteins, while the internal levels of H2O2 remained unaffected in all alfalfa cultivars. Ghara-yonje cultivar which displayed maximum growth traits and other characteristics exhibited the highest increments in respect of antioxidant enzyme activities. These results indicate that Ghara-younger cultivate tolerance to salt stress, which is associated with enhanced oxidative defense system.
