Evaluation of Salt Stress Effect on Chlorophyll Fluorescence in Two Sugar beet (Beta vulgaris L.) under Salicylate Foliar Application

To study of salicylic acid effect on chlorophyll fluorescence parameters under salt stress condition an experiment was conducted in Split factorial based on randomized complete block design with three replications at Shahid Chamran University of Ahwaz research farm. In 4-leaf stage after full expanded leaves, simultaneous with 150 mM NaCl salt stress applying; the leaves of salicylic acid including 0, 0.5 and 1 mM was sprayed on the leaves early morning. Two cultivars (Jolge and Sharif) of sugar beet were used at this experiment. Growth analysis was done at vegetative stage and ripening. Salinity caused significant reduction in root and shoot dry weight, stomatal conductance, SPAD value,Ф PSІІ, qP and Fv/Fm. Also salt stress resulted in significant increase in NPQ. Treatment by salicylic acid caused significant increase of root dry weight, stomatal conductance conditions stress, SPAD value,Ф PSІІ, qP and Fv/Fm compared to not application of salicylic acid under salt stress conditions. According to the results of the Correlation, photochemical quenching excited electron energy (qP) and root dry weight (r = 0.56*) and shoot dry weight (r = 0.68**) stress conditions showed a significant positive correlation. Therefore this attribute can be used to screen for these cultivars under the conditions foliar salicylic acid.