Patterns of ion distribution in selected NaCl tolerant and normal lines of four grass species

Abstract

Selected NaCl tolerant and unselected control lines ofHolcus lanatus L.,Lolium perenne L.,Dactylis glomerata L., andFestuca rubra L. were grown in sand culture at 0, 100, 200, 250, and/or 300 ml m^-3NaCl for seven weeks. The tolerant lines of all four species produced significantly greater both shoot and root dry matter at all NaCl treatments compared with the unselected control lines. Na⁺, K⁺, Cl^-, Ca²⁺, and Mg²⁺ contents of leaf, stalk, and roots of each species were determined. The tolerant lines ofH. lanatus contained less Na⁺ and less Ca²⁺ but higher K⁺ in shoots, compared with the unselected line. By contrast theL. perenne tolerant line had higher Na⁺ and Cl^- contents at 250, and 300 mol m^-3 NaCl in shoots than the unselected line suggesting a halophytic nature of the tolerant line.D. glomerata accumulated greater quantities of ions compared with the other species examined. The tolerant line contained significantly less Cl^- but more K⁺ in its shoots than the unselected line. Na⁺, Cl^-, and K⁺ contents in the shoots of the tolerant line ofF.rubra were higher than in the unselected line shoots. Therefore selection for NaCl tolerance may provide useful material for examining the basis of tolerance.