Effect of NaCl on citrus cultivars

We investigated the effects of salinity stress-relief on the growth and mineral composition (leaf and root) of one-year-old seedlings of Cleopatra mandarin (Citrus reticulata Blanco) and Sour orange (Citrus aurantium [L]). Salinization reduced plant dry weight more in Sour orange than in Cleopatra mandarin plants, although there was no correlation between Cl and Na concentration in leaves and shoot fresh weight reduction. We observed that regulation of Na+ and Cl- uptake and transport from root to shoot appear to involve different mechanisms which break down during a long period of salinization. Salinity induced a decrease in K+, Ca2+ and total N in Cleopatra mandarin leaves and an increase in K+ in Sour orange leaves. Growth of both cultivars was not recovered totally in the relief period, since relative growth rates of recovered plants were lower than for control plants after 60 days of relief.