Ion Regulation in Different Organs of Melon (Cucumis melo) Genotypes under Salt Stress

The changes in ion acumulation with respect to the tolerance of salt stress were determined in melon (Cucumis melo L.). The study was performed in hydroponic conditions in growth chamber using salt tolerant (CU 196) and salt sensitive (CU 252) genotypes. Plants were subjected to 100 mM NaCl for 12 days. Fresh and dry weights were decreased by salinity. The genotypes exposed to 100 mM NaCI application developed different mechanisms to be protected against toxic effects of Na ion. Salt tolerant genotype CU 196 limited Na accumulation in all organs and acted selectively among ions. K and Ca concentrations was high in plant organs in which Na concentration were low and tolerant genotype had higher K/Na and Ca/Na ratios than sensitive genotype. The present results demonstrated that toxic ion, which Na could be stored in old leaves and having a restricted transposition of salt into young leaves as a diminishing disruptive influence of salinity. (C) 2012 Friends Science Publishers