Effects of Salinity and Nitrogen on Growth, Contents of Pigments, and Ion Accumulation of a Euhalophyte Suaeda Salsa in an Intertidal Zone and on Saline Inland

The different responses of two populations of Suaeda salsa (Linn.) Pall. (saline seepweed) from an intertidal zone and a saline inland zone to salinity [1 or 500mM sodium chloride (NaCl)] and nitrogen [N; 0.05, 1, or 10mM nitrate (NO3 -)-N] were investigated. Greater NO3 --N supply (10mM) increased shoot dry weight for the two populations of S. salsa, especially for S. salsa from the saline inland zone. Greater NO3 --N supply (10mM) increased the concentrations of chlorophyll and carotenoid in leaves and the NO3 - and potassium (K+) concentrations in shoots for both populations. Greater NO3 --N supply (10mM) increased shoot Na+ in S. salsa from the intertidal zone. In conclusion, S. salsa from the saline inland zone is more responsive to NO3 --N supply than the intertidal population. Greater NO3 --N supply can help the species, especially the intertidal population, to grow and to mediate ion homeostasis under high salinity.