Effects of salinity on antioxidant system in ten grape genotypes. Nayer Mohammadkhani1 and Nasser Abbaspour2*

Salinity is an important environmental factor that limits plant growth and production. Grape is classified as salt sensitive plants. The object of this study was to evaluate effects of salinity on membrane lipid peroxidation, antioxidant components, and antioxidative enzymes activity in ten grape genotypes native to the regions around Urmia Salt Lake.Malondialdehyde content and protective enzymes activities in roots and leaves of ten genotypes increased significantly (p≤0.05) under salinity. Salinity had an obvious effect on the accumulation of total phenolics content and induced phenylalanine ammonia-lyase enzyme activity in all genotypes. H6 showed low increases in Malondialdehyde content, also this genotype showed good enzymes activities and total phenolics content and PAL activity. There were significant positive correlations (p≤0.01, r2=0.7) between antioxidative enzyme activities, total phenolics content, and phenylalanine ammonia-lyase activity in the leaves of all genotypes. It seems that H6 showed a higher capacity to tolerate salinity compared to the other genotypes.