Interactive effects of increased phosphorus (P) with salinity were studied at the microculture level of African violet (Saintpaulia ionantha). Increased P from 0.5 to 2.0 mM in the medium was very effective to mitigate the adverse effects of increased NaCl salinity (0.0, 50, 75, 100 mM). Growth (shoot height, and dry mass) was significantly reduced with increased salinity, whereas increasing P improved growth with elevated salt concentrations. Leaf osmolarity was decreased (more negative) with salinity effect and it was increased (less negative) by P treatments. Percent ash was increased with salinity and it was not highly affected by P. Root number and root length were significantly reduced with increased salinity and improved with increased P. The percentage of shoot content of nitrogen (N), P, calcium (Ca), potassium (K), and mag-429 ORDER REPRINTS nesium (Mg) were reduced with elevated salinity level and this reduction was less as P concentration increased in the medium. Sodium (Na) was significantly increased with imposed salinity and its uptake was reduced with increased P level. Zinc (Zn), manganese (Mn), and copper (Cu) uptake were increased with elevated salinity level and reduced with elevated P level in the media. Increased NaCl level strongly reduced Fe uptake and P was very effective in increasing iron (Fe) uptake. An overall increased P was very effective in regulating macro and micronutrients uptake, counteracting the increased salinity adverse effects. We can conclude that P is a key element for studying the physiological responses of different plant species to salinity. Also in vitro cultures (a rigorously controlled system) could work as an efficient alternative for the study of salinity.

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Increased sodium chloride (NaCl) salinity effects on bitter almond (Amygdalus communis L.) growth, cell osmolarity and nutrient acquisition were studied in vitro. Elevated salinity from 0.0 (control) to 50, 75, 100 mM NaCl resulted in reduction in shoot growth (shoot height, shoot dry weight) and rooting (rooting percentage, root number, root length). Reductions in growth parameters were accompanied with reductions in leaf cell sap osmolarity from 24.0 (control) to 2 11.1 [at 100 mM NaCl]. Acquisition of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) was decreased with elevated salinity in the medium. On the other hand, micronutrients, zinc (Zn), copper (Cu), and manganese (Mn) as well as sodium (Na) increased with elevated salinity levels in the medium. Iron (Fe) was negatively affected and its acquisition was decreased with imposed salinity in the medium accompanied with increased chlorosis percentage. However, growth did not stop under the imposed treatments indicating a high tolerance of bitter almond to salinity stress up to the levels used in this study. Results also support the efficiency of a microculture (in vitro) system for the study of salinity tolerance.