ABSTRACT
Norway spruce [Picea abies (L.) Karst.] seed lots from populations growing on acid soil in the Black Forest (BF), and from a calcareous soil in the Schwäbische Alb (SA), West Germany, were grown in perlite and treated with 0 and 6 mM Al. Some of the plants were inoculated with the fungus Paxillus involutes Fr., while some were not. Fungus was associated with the roots of the inoculated plants, but mycorrhizas did not form. Mineral element distribution in the roots was investigated using X-ray microanalysis of freeze substituted sections in TEM. Seven elements were detected: aluminium, silicon, phosphorus, sulphur, chlorine, potassium, and calcium. Aluminium was almost entirely confined to the cortical cell walls, and was not detectable inside the endodermis. The presence of P. involutus significantly increased aluminium concentrations in the cortical cell walls of both seed lots, while silicon concentrations in the aluminium-tolerant (BF) plants increased in response to aluminium treatment.
ABSTRACT
A salt-tolerant callus line of Lycopersicon peruvianum has been obtained by exposing the cells, in suspension cultures and then in callus, to increasing concentrations of NaCl (50-350mM). This selected line grew better than the nonselected line at all levels of NaCl. Moreover, this selected line grew better in media containing salt than in those without it. It retained its tolerance after subculture for 3 passages (3 months) on salt-free medium. The growth of the selected line in mannitol was similar to that of the nonselected line, which suggested that the superiority of the selected line under salt stress was not due to osmotic stress tolerance. The ions SO 4 (--) and K(+) were highly toxic to L. peruvianum root callus, while Na(+), Mg(++) and Cl(-) were less toxic.
