Drought Stress in Iranian Endemic Savory (Satureja rechingeri): In vivo and In vitro Studies

Abstract

The importance of different species of savory is due to having phenolic compounds such as carvacrol and thymol in the essential oil and rosmarinic acid in the extract, having strong antioxidant and antimicrobial effects. This study was conducted on five ecotypes of <em>Satureja rechingeri</em> in <em>in vitro</em> and <em>in vivo</em> experiments. After determining the best shooting and rooting medium, micropropagation was done and clones were prepared. Water stress treatments were prepared by increasing agar up to 100% followed by selecting the most tolerant and sensitive clones. In the <em>in vivo</em> experiment, effect of water stress was studied in a greenhouse with irrigation withhold and sampling at five stages. Ten morphological and physiological characters were recorded from both experiments. The tolerant clone had superior tolerance to water deficit. Increasing the agar concentration up to 66% had no effects on rooting and the growth rates of shoots but more increase led to a sharp reduction in the growth rate and root differentiation. In the greenhouse, the tolerant clone was tolerated the stress up to nine days without showing any symptoms, but the continuation of stress led to a sharp increase in proline and soluble sugars and the reduction of plant pigments and leaf osmotic potential. This research was a kind of drought simulation at <em>in vitro</em> condition, performed for the first time for identification and screening of drought tolerant clones of savory.<br />