The effect of salt stress on ion accumulation, photosynthesis and compatible solute contents in four grapevine (Vitis vinifera) genotypes

Salinity tolerance of four grape genotypes [GharaUzum, Hosseini, AghUzum and Keshmeshi] was studied under various salinity levels (25, 50 and 100 mM NaCl). As a result, growth indices were significantly (P<0.05) reduced by salinity, whereas Cl- and Na+ contents in the plant parts were increased. Cl- accumulation exceeded than that of Na+ in all treatments. Among the genotypes studied, GharaUzum and Keshmeshi had the lowest and highest Cl- concentrations in the leaf lamina, respectively. Photosynthesis and transpiration rate as well as stomatal conductance were greatly reduced by salinity and were shown to be highly correlated with leaf Cl- content. GharaUzum showed lower reduction in photosynthesis parameters. Soluble sugars, proline and glycine betaine contents increased in the leaf lamina of all the genotypes studied treated with moderate salinity (50 mM). In conclusion, the results showed that GharaUzum and Keshmeshi had the highest and lowest salt stress tolerance among the genotypes studied, respectively.