Growth, water status and nutrient accumulation of seedlings of Salvadora oleoides (Decne.) in response to soil salinity

We investigated the response of Salvadora oleoides Decne. (Salvadoraceae), a dominant tree in the arid regions of western India and Pakistan, to a range of soil salinities. Greenhouse experiments were conducted to assess the effects of soil salinity on seedling emergence, growth, water status, proline content and mineral accumulation. Sodium chloride was added to the soil and salinity was maintained at 0.2, 3.9, 6.2, 8.1, 10.0, 11.9 and 13.9 dS m(-1). Salinity caused reduction in water content and water potential of tissues, which resulted in internal water deficit to plants. Consequently, seedling growth decreased and proline content in tissues increased with increase in salinity. This species has high selectivity for potassium but lacks effective mechanisms to control net uptake of sodium and its transport to shoots. Phosphorus, calcium and magnesium content in tissues significantly decreased while nitrogen content increased as salinity increased. We discuss changes in tissues and whole-plant accumulation patterns of nutrients, as well as possible mechanisms for avoidance of sodium toxicity in this species in response to salinity.