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Abstract Soil salinity, aridity, increasing atmospheric CO2 concentration and heavy metal pollution are among the major issues receiving - at present - greatest world concern. Excessive salinity is an edaphic factor that limits the distribution of plants in certain natural habitats. Also, salinity is a serious and potential problem in the irrigated lands in the arid and semiarid zones in many parts of the world. Nearly fourty percent of the world’s land surface can be categorized as having potential salinity problems, most of these areas are confined to the tropics and Mediterranean regions (World Resources, 1987). In general, salinity reduces the growth of salt - sensitive glycophytes and affects many aspects of metabolism of plants and results in several changes in their anatomy and morphology. The reduction in plant growth ’ by salinity may result from disturbances in the water balance, carbon/energy metabolism, nutrient uptake, reduction in dry matter allocation as well as changes in physiological and biochemical reactions or a combination of these (Greenway and Munns, 1980~ Flowers and Yeo, 1992; Marschner, 1995). Survival and growth of plants in saline environment are complex phenomenon that involves adaptive processes such as ion transport and compartmentation, osmotic solute synthesis and accumulation and protein turnover for cellular repair (Munns and Tennaat, 1986; Paul and Cockburn, 1989; Sanchez - Blanco et al., 1991). |