Hossin Abbaspour - Department of Biology, Faculty of Science, Damghan Branch, Islamic Azad University, Damghan, Iran
Halimeh Rezaei - Department of biology, Islamic Azad University, Damghan Branch, Damgha, Iran

Objective: In order to study the effect of drought stress, salicylic acid (SA) and jasmonic 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, theeffects drought stress, salicylic acid and jasmonic acid on Hill reaction, chlorophyll a, chlorophyll b, chlorophyll a+b, â-carotene and Xanthophyll were significant. Drough stress increased the content of â-carotene (1.83 ) and Xanthophyll (2.60 ). The 50 (µM) foliar application of jasmonate and salicylic acid under normal irrigation condition gained to maximum amounts of Hill reaction, chlorophyll a, chlorophyll b, chlorophylla+b, â-carotene and xanthophyll. According to the results, exogenous salicylic acid andjasmonic acid application can improve drought tolerance in moldavian dragonhead (Dracocephalum moldavica L.).

Drought stress ، Jasmonic acid ، Moldavian dragonhead ، Salicylic acid