Effects of salinity stress on morphological and physiological parameters in three Eucalyptus species

Most salinity problems causes by NaCl distribution in dry lands, beaches and water resources. This research was carried out to estimate salinity resistance of three Eucalyptus species: Eucalyptus largiflorens¡ E. sideroxylon and E. wandoo. Five NaCl levels (0, 50, 100, 150 and 200 mM) of salinity were used in three replications by a factorial experiment model based on a completely randomized design. Sampling were made from terminal leaves of the selected trees. Different characteristics such as pigments, total chlorophyle, chlorophyle a and b, carotene, soluble sugar and prolin, glycine betaine, growth parameters such as biomass, leaf area, relative water content, water saturation difference, specific leaf area and leaf water content per unit leaf area were recorded. Increased salt stress lead to increment of prolin level, soluble sugar, withering, falling, dried leaves and decrement of pigments and growth parameters in the species. Between the studied species, E. largiflorens showed the most salt stress tolerance, although for prolin, soluble sugar, pigments, glycine betaine, R/S, RWC, wet and dry root and shoot weight, had the highest values and for the withering, falling and dried leaves had the lowest values.