Interactive effects of water stress and gibberellic ai cd on mineral composition of fenugreek plant

ABSTRACT

12 days-old fenugreek plants were grown in stressed nutrient solutions imposed by NaCl or PEG 4000 to obtain isosmotic solutions of osmotic potentials ranging from 0 to -8 bars. The different stress levels were applied from the onset of germination in treatment I, while in treatment II, the stress levels were applied after 5 days of germination at zero stress level. The interactive effects between GA3, as a presoaking medium, and water stress was also studied. At the lowest osmotic potential, the shoots of salt-stressed plants from both treatments had higher sodium and chloride contents and lower potassium, calcium, magnesium and total phosphorus levels. Such ionic composition was altered in PEG-stressed plants, where the contents of sodium, magnesium and chloride were greatly reduced and balanced by an increase in the level of potassium, calcium and total phosphorus compared with those under saline condition. A similar pattern of ionic changes was demonstrated in GA3-presoaked plants when the external osmotic potential level decreased Na+, K+, Ca2+, Cl- and insoluble phosphorus fraction, it decreases the Mg2+ level under control and each stress condition