Growth, Osmotic Adjustment, and Nutrient Acquisition of Bitter Almond Under Induced Sodium Chloride Salinity In Vitro

Abstract

Increased sodium chloride (NaCl) salinity effects on bitter almond (Amygdalus communis L.) growth, cell osmolarity and nutrient acquisition were studied in vitro. Elevated salinity from 0.0 (control) to 50, 75, 100 mM NaCl resulted in reduction in shoot growth (shoot height, shoot dry weight) and rooting (rooting percentage, root number, root length). Reductions in growth parameters were accompanied with reductions in leaf cell sap osmolarity from −4.0 (control) to −11.1 [at 100 mM NaCl]. Acquisition of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) was decreased with elevated salinity in the medium. On the other hand, micronutrients, zinc (Zn), copper (Cu), and manganese (Mn) as well as sodium (Na) increased with elevated salinity levels in the medium. Iron (Fe) was negatively affected and its acquisition was decreased with imposed salinity in the medium accompanied with increased chlorosis percentage. However, growth did not stop under the imposed treatments indicating a high tolerance of bitter almond to salinity stress up to the levels used in this study. Results also support the efficiency of a microculture (in vitro) system for the study of salinity tolerance.