Biochemical Response of Apple Dwarf Rootstock to Salinity Stress

Excess salt in the soil solution may adversely affect plant growth either through osmotic inhibition of water uptake by roots or specific ion effects. Specific ion effects may cause direct toxicity or alternatively, the insolubility or competitive absorption of ions may affect the plants nutritional balance. At these condition plants use different mechanisms for adaptation. One potentially important mechanism is the components of osmotic adjustment, such as soluble sugars and praline amino acid accumulation in plant tissues at response to biotic stresses. The increasing interest in the cultivation of apple (Malus.pomila L.) in moderate climates and in the west Azerbaijan province of Iran requires better understanding of the salinity effects especially in the apple dwarf rootstocks. The aim of this work was to study of biochemical response of the external and local apple dwarf rootstocks in elevated Nacl concentrations and select the best rootstock for apple cultivation in west Azerbaijan condition. The experiment was carried out under natural greenhouse conditions. Annual seedlings of four apple dwarf rootstocks were grown in pots containing prelate and sand (ratio 1:1) in April-May 2008. The plants were irrigated with Hoagland nutrient solution containing 0, 2, 4 and 6 do/m Nalco. In the leaves of plants proline and soluble sugars accumulation were determined. The results of this work indicate that increasing salt concentration in the nutrient solution leads to: (a) an increase concentration of proline amino acid and soluble sugars content in leaves of all rootstocks (b) a linear increase of chloride and sodium content in the leaves of all rootstocks (c) The highest praline and soluble sugars there were in leaves of Gami almasi and Milling 9 rootstocks (d) the highest praline and soluble sugars there were in 6 ds/m salinity.