Physiological and biochemical characterization of Acacia stenophylla and Acacia albida exposed to salinity under hydroponic conditions

Abstract

Soil salinity is considered a serious environmental issue in many countries of the world including Pakistan. A hydroponic experiment was carried out to study different mechanisms of salinity tolerance in two acacia species namely Acacia stenophylla and Acacia albida. Uniform seedlings of both the species were grown for 28 days in half strength Hoagland’s nutrient solution with 0, 100 or 200 mM NaCl concentrations. The results revealed that shoot biomass was decreased by 21% and 29% at the lower salinity level (100 mM NaCl), and by 44% and 55% at the higher salinity level (200 mM NaCl) in A. stenophylla and A. albida, respectively. The respective reductions in root biomass of both the species were 20% and 29% at the lower, and 36% and 54% at the higher salinity level. Among different antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), the highest increase (6 folds) was observed in SOD activity in the case of A. stenophylla. This study concludes that A. stenophylla i...