SALT TOLERANCE IN THE TRITICEAE - K/NA DISCRIMINATION IN SYNTHETIC HEXAPLOID WHEATS

Ion concentrations were measured in the leaves of synthetic hexaploid wheats and their parents growing in saline hydroponic culture. The synthetic hexaploids contained genomes from a tetraploid wheat (Triticum diccocum, T. durum, T. araraticum or T. timopheevi) and from a diploid species (T. monococcum, T. urartu, T. boeoticum or Aegilops squarrosa). Leaf Na concentrations were low, and K concentrations high, in Ae. squarrosa, T. araraticum and all of the synthetic hexaploids, but high in T. dicoccum and T. durum. At low salinities leaf Na concentrations were particularly high in T. durum in comparison with the other species. These results suggest that the enhanced K/Na discrimination character, originally found in Ae. squarrosa and BBAADD genome hexaploid wheats, is also present in diploid wheat and in GGAA genome tetraploid wheats. It is suggested that this character has been lost in the evolution of the BBAA genome tetraploid wheats. © 1990 Oxford University Press.