Growth, water status and nutrient accumulation of seedlings of Cassia fistula L. in response to soil salinity

Abstract

Greenhouse experiments were conducted to assess the effect of soil salinity on emergence, growth, water status, proline content and mineral accumulation of seedlings of Cassia fistula L. (Fabaceae). NaCl was added to the soil and salinity was maintained at 0.2, 2.1, 3.9, 6.2, 8.1, 10.0 and 11.9 dSm-1. Salinity caused reduction in water content and water potential of tissues that resulted in internal water deficit to plants. Consequently, seedling growth significantly decreased as salinity increased. Proline content in tissues increased as salinity increased. There were no effective mechanisms to control net uptake of Na+ and subsequently its transport to shoot tissues. Na content significantly increased in tissues as salinity increased. N, K and Ca content in tissues significantly decreased as salinity increased. Changes in tissues and whole-plant accumulation pattern of other nutrients, as well as possible mechanisms for avoidance of Na toxicity in this species in response to salinity, are discussed.