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

Abstract

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 500 mM sodium chloride (NaCl)] and nitrogen [N; 0.05, 1, or 10 mM nitrate (NO₃ ⁻)‐N] were investigated. Greater NO₃ ⁻‐N supply (10 mM) increased shoot dry weight for the two populations of S. salsa, especially for S. salsa from the saline inland zone. Greater NO₃ ⁻‐N supply (10 mM) 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 (10 mM) 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.

Keywords:

• Carotenoids
• chlorophyll
• halophytes
• NaCl
• NO₃ ⁻

Acknowledgments

We are thankful to the journal editor and the anonymous reviewer for their critical reading and edits to the manuscript. Financial support from the Foundation of Excellent Young Scientists of Shandong Province (2006BS06002) and the State High Technological Research and Development Plan of China (2007AA091701) is greatly appreciated.