Effect of Exogenous Application of Hydrogen Peroxide on Drought Tolerance of Glob Amaranth (Gomphrena globosa L.)

Drought is one of the important environmental stresses that reduce the crop growth. Oxidative stress is a secondary stress due to drought and other abiotic stresses. In order to study the effect of exogenous application of hydrogen peroxide on drought tolerance of glob amaranth (Gomphrena globosa L.)، an experiment was conducted in greenhouse conditions. This study was designed as factorial based on completely randomized design with 3 replications. Different concentrations of hydrogen peroxide (0، 2. 5 and 5 mM) and three levels of irrigation intervals (after 4، 7 and 10 days) were treated in this study. The results showed that foliar application of hydrogen peroxide can improve shoot and root dry weight and alleviate adverse effects of drought stress. With increasing drought stress stomatal conductance، flower number، total chlorophyll and root volume decreased significantly. So that the lowest of these characterestics was in the irrigation after 10 days. Interaction effects of drought and hydrogen peroxide in shoot dry weight was significantly different in 5% level and in electrolyte leakage، relative water content، free proline and total root length was significantly different in 1% level. In control (4 day irrigation interval) with increasing hydrogen peroxide of 2. 5 mM، shoot dry weight and total root length increased 20% and 91%، respectively. In control، with increasing hydrogen peroxide to 5 mM total chlorophyll was increased 30. 8% compared to 0 mM hydrogen peroxide application (control). The final result showed that foliar application of hydrogen peroxide decreased the adverse effects of drought stress.