Mango rootstocks with good tolerance to saline conditions in the soil have not been selected so far. The rootstock '13/1' has relative high salt tolerance under field conditions, but the reasons for this are not fully known. Therefore, '13/1' was tested to characterize the morphological and physiological reactions to increasing saline stress conditions. Rooted cuttings were grown in the greenhouse and treated with 20, 40, 60 mM/l Na+ as NaCl and Na2SO4. The reduction of vegetative growth was stronger in NaCl treatments than in Na2SO4 treatments. Salt symptoms occurred later with Na2SO4 treatment. Salinity significantly reduced the average leaf area, but the leaf number was increased at low saline conditions. Mineral analysis in roots, stem, old leaves, shoots and young leaves showed high Na+ contents in young plant parts. The Na+ contents in roots with Na2SO4 treatment were significantly higher than with NaCl. The uptake of SO4 2- was half that of Cl- and the translocation of Na+ in the upper plant parts was reduced with SO4 2- as anion. In both salt treatments transpiration was significantly reduced during 8 weeks of saline conditions. The reduction was stronger with NaCl than with Na2SO4 treatment.
- tree architecture