Abstract

Pepper plants ( Capsicum annuum L. cv. Orlando) were used to compare the effects of NaCl and KCl on osmotic adjustment, water relations, and gas exchange. Thus, two different saline treatments, 60 mM NaCl and 60 mM KCl, were applied and different measurement times (1, 2, 3 and 10 days) were assayed in order to determine the effect of the treatment duration on the parameters studied. Reductions in root hydraulic conductance, stomatal conductance and net assimilation of CO 2 were observed after NaCl and KCl addition. Mineral composition of leaf sap was also determined and it was observed that Cl − and NO 3 − were the main anions used by pepper plants to achieve the osmotic adjustment. Also, salinity induced a decrease in the concentrations of Ca 2+ and Mg 2+ in leaves. Osmotic regulation by organic solutes was also determined, by analysis of the contents of sugars and amino acids. It appeared that sucrose was the main carbohydrate accumulated by the plants in order to maintain turgor. However, the degree of osmotic adjustment observed indicated that changes in leaf turgor occurred after either saline treatment, for all application times, suggesting that pepper plants could not adjust their water relations sufficiently. Thus, Na + and K + exerted a toxic effect on pepper plants mainly by affecting the plant water relations, although the effect of Na + on water relations parameters was more significant than that of K +.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.