CHARACTERISTICS OF SALTS SECRETED BY TAMARIX APHYLLA

Abstract

The composition and concentration of salts secreted by the salt glands of Tamarix aphylla L. grown under controlled nutrient conditions were determined. Eight ions, Na, K, Mg, Ca, Cl, NO 3 , HCO 3 , and SO 4 , constituted 99 % + of the dry weight of salts secreted by plants grown on half‐strength Hoagland's solution. The divalent cations Mg and Ca accounted for most of the cations; HCO 3 comprised about 60 % of the anions. The micronutrients B, Mn, Cu, Zn, and Mo were present in enriched concentrations in the secretion. The composition of the secretions was highly dependent on the composition of the root environment. The predominating cation in the saline culture solutions was also the predominant cation secreted. The accompanying anion in the culture solution influences the cation composition of the secreted salt. The concentration of the salt gland secretion averaged 0.5 n , a 50‐fold increase in concentration over the nutrient solution in which the plants were grown.