The Effect of Zinc Oxide Nanoparticles on the Physiological Characteristics in Pepper (Capsicum annum L.) under Salinity Stress

In this study, the effect of spraying of Zinc oxide nanoparticles at three concentrations (0, 1000 and 2000 ppm) on the response of Capsicum annuum L. to different levels of salinity (0, 25, 50 and 75 mM NaCl) was evaluated. The experiment was carried out as factorial based on randomized complete block design with four replications in pot culture conditions. The high concentration of salt and Zinc oxide nanoparticles reduced the amount of chlorophyll, carotenoids, total phenol, leaf dry weight, proline content, total soluble carbohydrate, plant height, stem diameter and catalase enzyme activity but increased the amount of malondealdehyde (MDA). Rising the salinity level to 50 mM, increased the soluble carbohydrates content but further increase to 75 mM salinity led to decrease in the soluble carbohydrates content. The interaction of salinity and Zinc oxide nanoparticles was significant on chlorophyll, proline, malondealdehyde (MDA), total phenol, carotenoids, and soluble carbohydrates concentrations, and leaf dry weight. The result of this experiment showed that Zinc oxide foliar application in the form of nanoparticles is potent to reduce the damages of salinity to pepper.