الفهرس 
Physiological Response and Nutrint Uptake of different tomato cultivars grown in hydroponic culyure under salinity stress.Only 14 pages are availabe for public view
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Abstract
Agriculture in the presence of salinity is one of the most important environmental constraints that not only account for large decrease in the yield of a wide variety of crops all over the world but also limits the use of land for agricultural purposes.
The negative effects of salinity on growth and productivity of plants are osmotic effect that results from the relatively high solute concentrations in the growing medium, specific ion toxicity resulting from high Na+ and Cl- ion concentrations that are inimical to plants, nutritional imbalance, and production of reactive oxygen species (ROS), which disturbs photosynthesis and physiology of the plants.
Identification of plant genotypes capable of increased tolerance to salt and incorporation of these desirable traits into economically useful crop plants may reduce the effect of salinity on productivity. Genotypes sensitive or tolerant to salinity differ in the rate at which the salt reaches toxic levels in leaves, timescale is days or weeks or months, depending on the species and the salinity level.
The current study aimed to:
i.Screening of some local tomato cultivars available in the Egyptian market for their salt tolerance.
ii.Understand the response of the most salt tolerant, moderate, and sensitive cultivars to the effect of salinity strength (Concentration and time of exposure).
iii.Investigate the effectiveness of citrate amendment (Ca, Mg and K) to alleviate salinity stress in tomato.
Experimental design
Three experiments were conducted at the field research station of the greenhouse in the faculty of Agricultural, Alexandria University, Egypt. Seeds of six tomato cultivars (Lycopersicon esculentum Mill.) were obtained from the Egyptian market (Alexandria). These cultivars were Cult. 010, Sama, Princisa, Cult.1077, Elesa, and Cult.380.
Tomato seeds were germinated in foam trays and were irrigated with tap water, covered with black plastic sheets for one week. Trays were left in the greenhouse and the geminated seedlings were irrigated with half-hoagland nutrient solution for another two weeks.
Tomato seedlings (21days old) were transplanted into plastic pots (20 cm height and 24 cm diameter) containing 5.5 liter freshly prepared Hoagland solution.
Transplanting period was 2 weeks, tomato plants were grown in full-Hoagland nutrient solution supplied with salinity treatment until harvest.