Impact of Salinity Stress on Photochemical Efficiency of Photosystem II, Chlorophyll Content and Nutrient Elements of Nitere bush (Nitraria schoberi L.) Plants

Abstract

Abstract.Salinity is one of the major stresses and, especially in arid and semi-arid regionscan severely limit plant production.The present study was carried out to evaluate the impact of salinity stress on some physio-biochemical parameters in niter bush plants. Thus, an experiment was carried out under natural condition and salinity stress was induced by a combination of different salts (NaCl, MgCl2and CaCl2) at four levels. The salinity treatments were: Control (untreated, Ctrl), 150 mMol (low salinity, LS), 300 mMol (medium salinity, MS) and 450 mMol (high salinity, HS)of the combined salt. In this study, photosynthetic apparatus of N. schoberi, was damaged to a certain extent, as observed from leaf Chl FPssuch as F0, Fmand Fv / Fm.A significant alteration in chlorophyll content of the leaf was not noticed with increasing soil salt content up MS and thereafter, it significantly declined at HS.The reduced level of total chlorophyll content under salt stress condition can be attributed to chloroplastid membrane deterioration, leading toward lesser accumulation of chlorophyll. The amount of inorganic ions in niter bush plant leaves altered with an increase in salinity stress.The concentration of Na+and Cl-steadily increased and onthecontrary theconcentrations of K+, Ca2+and Mg+showed significantdecreases only at HS. This phenomenon is explainable by inhibition of K+uptake by high Na+levels, because these cations are transported by the same proteins. In our experiments we did not observe significant differences between control plants and those grown in presence of 300 mMol saltkg-1dry soil(DS). Thus, niter bush is considered to be a salt tolerant species.