الفهرس 
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Abstract
The experiments were carried out in the Laboratory and glasshouse of the Agricultural Botany Dept., Fac. of Agriculture, Mansoura Univ. during the growing seasons of 2007-2009, to understand and gain knowledge on the germination and seedling growth, plant growth, phyotochemical constituents as well as yield and its components behavior of sweet pepper under different sources of salinity i.e. NaCl, CaCl2 and their combination (1:1 w/w) at 2000 or 4000 mg/L; and how to minimizing the harmful effects through pre-soaking seeds in vitamins (Ascorbic acid or α-tocopherol at 50 or 100 mg/L) or bio-regulator (Salicylic acid at 75 or 150 mg/L) or Yeast extract at 1000 or 2000 mg/L. First experiment: The present experiment was planned to study the effect of presoaking sweet pepper seeds in vitamins (Ascorbic acid or α-tocopherol) at 50 or 100 mg/L or bio-regulator (Salicylic acid) at 75 or 150 mg/L or (Yeast extract) at 1000 or 2000 mg/L on seed germination, seedling growth as well as some biochemical aspects under non-saline or different sources of salinity. Second experiments: The following experiments were conducted to study the influence of soaking the seeds of sweet pepper plant in selected chemicals used i.e. bio-regulator (salicylic acid), vitamins (ascorbic acid or α-tocopherol) or yeast extract at the same levels mentioned in the first experiment, under non-saline or saline conditions. The most important results achieved are summarized as follows: 1. Low salinity level (2000 mg/L) of all of salinity types (NaCl, CaCl2 and their combination) increased seed germination percentage, germination performance index, seedling length, seedling fresh and dry weights, water content, enzymes activity (peroxidase and catalase), photosynthetic pigments concentrations, growth parameters (plant height, root length, shoot and root fresh as well as dry weights, number of leaves as well as leaf area), N, P, K+ and Mg2+ concentration as well as K+/Na+ ratio in sweet pepper root, shoot, and fruits, fruits number and fresh weight per plant on the early 4th picking and total yield as well as total soluble solids (TSS %) in fruits. While, plants grown under NaCl salinity did not produced fruits in the early 4th picking. 2. In the contrast, increasing salinity levels caused a significant decrease in this respect. In addition, under NaCl+CaCl2 (1:1) were more effective followed by CaCl2 and NaCl. Moreover, pre-soaking seeds, in most cases, gave a positive effect on growth parameters. Furthermore, salicylic acid at 75 mg/L, ascorbic acid at 50 mg/L or α-tocopherol at 100 mg/L was more effective in this respect. 3. Anatomically, low level of all salinity types (2000 mg/L) increased midrib region thickness, lamina thickness, thickness of palisade and spongy tissues as well as upper and lower epidermis width, main vascular bundle dimensions, stem diameter, pith diameter, cortex thickness, width of epidermis cell and vascular bundles dimensions (length as well as metaxylem vessel diameter). In addition, increasing salinity levels of all salinity applied types decreased the number of stomata and the stomatal density on both surfaces of sweet pepper leaves. Moreover, high salinity level (4000 mg/L) decreased most of the anatomical parameters. 4. On the other hand, pre-soaking seeds in selected chemicals used, in most cases, gave a positive effect on the leaf and stem structure and AsA at 50 mg/L or SA at 75 mg/L was the most effective in this respect.