Effects of Salicylic acid and Jasmonic acid on Hill Reaction and Photosynthetic Pigment (Dracocephalum Moldavica L.) in Different Levels of Drought Stress

In order to study the effect of drought stress, salicylic acid (SA) and  jasmonic acid (JA) foliar application on Hill reaction and photosynthetic pigments. 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). 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 jasmonate  and 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.).