الفهرس 
Introduction
Salinity and its EffectsOnly 14 pages are availabe for public view
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Abstract
The present study is planned as an attempt to minimize the harmful effects of salinity levels (1500, 3000 and 6000 ppm NaCl) on sorghum and sweet pepper plants growing in NFT, by glycinebetaine (at 2000 or 4000 ppm) and ascorbic acid (at 50 or 100 ppm) . The most important results are summarized as follows: 1. Low salinity level (1500 ppm NaCl) led to increased germination percentage and shoots fresh weight of sorghum as well as plant height, root dry weight and number of leaf per plant of sweet pepper. In contrast, low salinity level decreased germination percentage, root length, root fresh weight, shoot (fresh and dry) weights and leaf area of sweet pepper, as well as decrease plant height and root length, root (fresh and dry) weight and shoot dry weight, number of leaf per plant and leaf area of sorghum. 2. Under moderate and high salinity levels decreased all mentioned above. In addition, all salinity levels led to decreased chlorophyll a, b and total chlorophyll concentrations as well as K+ concentration in (shoot and root system) of two species pepper and sorghum plants. Meanwhile, increased Na+ concentration as well as Na+ /K+ ratio (shoot and root system). 3. Presoaking seeds of sweet pepper and sorghum grains or presoaking plus spraying with glycinebetaine or ascorbic acid led to increase all mentioned above. On the other hand, decreased Na+ concentration and Na+ / K+ ratio of sweet pepper and sorghum plants. 4. Low salinity level increased the thickness of midrib region and leaf blade. Meanwhile, increasing salinity levels decreased all anatomical characters. 5. GB or AsA (presoaking or presoaking plus spraying) led to increased significantly all characters mentioned above. 6. Under NaCl saline conditions induced clear changes in the ultrastructure of organelles in plant cell of sweet pepper and sorghum plants. 7. Presoaking of sweet pepper seeds and sorghum grains (or presoaking plus spraying) with GB or AsA led to reducing the harmful of salinity on ultrastructure mesophyll cells compared to plant treated by NaCl salinity.