Preliminary Study on the Salt Resistance Mechanisms of Populus euphratica

摘要

Experiments were carried out with two-year old seedlings of two genotypes: P. euphratica Olive and its hybrid (P. talassica Kom x (P. euphratica+ Salix alba L)) which were subjected to salt stress by applying 50 mM and 200 mM NaCl solutions. Four saltresistance mechanisms were identified in P. euphratica: (1) active reduction of leaf area and number; (2) development of phyllode succulence (specific leaf area decreased with salt treatment); (3) exclusion of salt ions from stem and leaves (leaf Na~+ and Cl~ contents of high salt treated P. euphratica were only one third of that of the hybrid); (4) selective absorption of K~+ and Ca~(2+) ions to counter the toxicity of salt ions and maintain membrane integrity (leaf K~+ contents of P. euphratica werenot influenced and stem Ca~(2+) contents even increased with the increase of salt treatments).