Abstract
The effects of arbuscular mycorrhizae fungi (AMF), putrescine (Put), and their combination on essential oil (EO) content, chlorophyll (Chl), carotenoid and EO chemical compounds of cumin (Cuminum cyminum L.) were studied under optimal and drought stress conditions. The foliar application of Put or inoculation with AMF significantly (P ˂ 0.05) increased seed yield, EO content, EO yield, Chl a, Chl b, total Chl, and carotenoid. Moreover, AMF or Put application increased cuminaldehyde, limone, and β-Pinene and decreased γ-Terpinene, o-Cymene, and linalool concentration in cumin plants compared to non-treated plants in both optimal and drought stress conditions. However, the highest EO content, EO yield, Chl a, Chl b, total Chl, carotenoid, and major EO chemical components were obtained when AMF and Put were used together under optimal and drought stress conditions. This study showed that Put and AMF can be co-applied to the cumin plant to significantly improve drought tolerance in field conditions greatly.