M.A. Thesis:

Priming effect on plant response to salinity Garadagh

In this experiment, the response of two rangeland species Nitraria schoberi and Panicum antidotale to different levels of salinity were investigated in greenhouse of Islamic Azad University of Sabzevar. A factorial experiment in a randomized complete block design with three replications was used. Experimental factors included two rangeland species Nitraria schoberi and Panicum antidotale and six levels of salinity (control), 50, 100, 150, 200 and 250 mM NaCl. The results showed that leaf chlorophyll index of Panicum antidotale was significantly higher than Nitraria schoberi. With increasing salinity up to 100 mM, leaf chlorophyll index increased and then decreased. The lowest leaf chlorophyll index was observed in 250 mM salinity level. The results showed that shoot fresh and dry weight loss was appropriate to increase the level of stress in both species. With increasing salinity, plant height in Panicum antidotale was declined, but in Nitraria schoberi increased up to 150 mM salinity level and then decreased. Root volume, total root area, total root length and root dry weight of Nitraria schoberi increased with increasing salinity up to 50 mM and then decreased. Howevere, the root volume, total root area, total root length and root dry weight of Panicum antidotale increased up to 150 mM salinity level and then decreased. In both species, with increasing salinity levels, electrolyte leakage increased, but this increase was more intense in Nitraria schoberi. Relative water content of leaves in Panicum antidotale increased up to 100 mM NaCl level and then decreased, but in Nitraria schoberi there were no significant differences between salinity levels from zero to 200 mM NaCl for the relative water content. Increasing salinity to 250 mM significantly decreased relative water content of leaves in Nitraria schoberi. According to the results, salt tolerance methods were different between Nitraria schoberi and Panicum antidotale and both plant resistance to salinity were favorable.

Keywords: Panicum antidotale, salinity stress, Nitraria schoberi, relative water content, electrolyte leakage