Salt Tolerance in the Triticeae: K/Na Discrimination in<i>Aegilops</i>Species

Abstract

Inorganic ion concentrations were measured in the leaves of Aegilops species growing in 50 or 75 mol m−3 NaCl (+2.5 or 3.75 mol m−3 CaCl2). The low leaf Na and high leaf K concentrations characteristic of the enhanced K/Na discrimination character, originally found in Aegilops squarrosa and in hexaploid wheat, were also found in other Aegilops species containing the D genome, but not in Ae. ventricosa. The S genome diploid Aegilops species (section Sitopsis) all lacked the enhanced K/Na discrimination trait, as did the C genome species Ae. caudata and the N genome species Ae. uniaristata. Most of the U genome species (section Polyeides), except Ae. biuncialis, Ae. kotschyi and Ae. variabilis, also exhibited the trait. Examination of amphiploid hybrids suggested that the trait was dominant in crosses involving Ae. squarrosa or Ae. umbellulata with other species in which the trait was absent.