Effects of salt stress on nitrogenase activity and growth of four legumes
The effects of salt stress on nitrogenase (N2-ase) activity, growth and nitrogen content ofVicia faba (L.),Medicago sativa (L.) Merrill,Glycine max andVigna sinensis (L.) were investigated. Four levels of salinity were applied and salt treatments were imposed on inoculated and N-fertilized plants.M. sativa tolerated mild levels of salinity but higher salt concentrations depressed N2-ase activity of this species. The other three legumes were considerably affected by salt treatments, and N2-ase activity was significantly reduced by salinity.
Vicia faba, carrying elongate nodules, could restore a partial N2-ase activity upon recovery from salt stress whereasG. max andV. sinesis, both with spherical nodules, could not regain significant activity when salinity was removed.
Salt stress retarded growth of both inoculated and N-fertilized plants. The nitrogen content of both treatments was also affected by salinity and the effect was more severe for inoculated than N-fertilized plants.
KeywordsSalt Stress Nitrogen Fixation Salt Treatment C2H2 Reduction Faba Plant
- Abdel Wahab, A. M., Zahran, H. H.: The effect of water stress on N2(C2H2) fixation and growth ofMedicago sativa.-Aota agron. (In press), 1980.Google Scholar
- Allen, O. M.: Experiments in Soil Bacteriology.-Burgess Publishing Co., Minneapolis 1959.Google Scholar
- Bernstein, L., Ogata, G.: Effects of salinity on nodulation, nitrogen fixation, and growth of soybeans and alfalfa.-Agron. J.58: 201–203, 1966.Google Scholar
- Hardy, R. W. F., Burns, R. C, Herbert, R. R., Holsten, R. D., Jackson, E. K.: Biological nitrogen fixation a key to world protein.-Plant Soil, Spec. Vol.: 561–590, 1971.Google Scholar
- Poljakoff-Mayber, A., Gale, J.: Ecological Studies 15. Plants in Saline Environments. Springer Verlag, Berlin-Heidelberg-New York 1975.Google Scholar
- Sprent, J. I.: Water deficits and nitrogen-fixing root nodules. - In:Kozlowski, T. T. (ed.): Water Deficits and Plant Growth. Vol. IV. Pp. 291–315. Acad. Press, New York-London 1976.Google Scholar
- Subbarao, N. S., Lakshmi-Kumari, M., Singh, C. S., Magu, S. P.: Nodulation of lucerne (Medicago sativa L.) under the influence of sodium chloride.-Indian. J. agr. Sci.42: 385–386, 1972.Google Scholar
- Wilson, J. R., Norris, D. O.: Some effects of salinity onGlycine javanica and itsRhizobium symbiosis.-In: Proceedings of the XI International Grassland Congress. Pp. 455–468. Paradise, Queensland, Australia, 1970.Google Scholar
- Zahran, H. H.: Studies on the effect of water stress and salinity on nitrogen fixation by some legumes.-M. So. Thesis, Assiut Univ. 1978.Google Scholar