1Department of Biology, Faculty of Science, Damghan Branch, Islamic Azad University, Damghan, Iran
2Department of biology, Islamic Azad University, Damghan Branch, Damgha, Iran
Objective: In order to study the effect of drought stress, salicylic acid (SA) andjasmonic acid (JA) foliar application on Hill reaction and photosynthetic pigments. Methods:Experiment was done as factorial on the basis of completely randomized design in 4 replications. Irrigation in 3 levels (FC,FC and FC), salicylic acid in 2 levels (0 and 0.5 mM) and jasmonic acid in 2 levels (0 and 50 µM). Results: The results indicated that, the effects drought stress, salicylic acid and jasmonic acid on Hill reaction, chlorophyll a, chlorophyll b, chlorophyll a+b, β-carotene and Xanthophyll were significant. Drough stress increased the content of β-carotene (1.83 ) and Xanthophyll (2.60). The 50 (µM) foliar application of jasmonateand salicylic acid under normal irrigation condition gained to maximum amounts of Hill reaction, chlorophyll a, chlorophyll b, chlorophyll a+b, β-carotene and xanthophyll.According to the results, exogenous salicylic acid and jasmonic acid application can improve drought tolerance in moldavian dragonhead (Dracocephalum moldavica L.).