Fennel (Foeniculum vulgare Mill) is a medicinal plant that all parts of it can be used in various industries such as food, chemical and pharmaceutical industries. To investigate the effect of vermicompost (VC: 0 and 5%), as an organic fertilizer, on the morphophysiological and biochemical characteris- tics of two fennel landraces (Shiraz and Urmia) under saline conditions (0, 40, 80, and 120 mM NaCl), a factorial experiment was conducted in green- house condition. After 3 weeks of culturing, plants were irrigated with experimental treatments until 5 weeks more. The results showed that salin- ity stress induced a significant decrease in leaf area, biomass, photosyn- thetic pigments content, relative water content, membrane stability index, minerals (Fe, K, Ca, and Mg) concentration, total protein content, and gib- berellin concentration of the shoot. A significant increase in malondialde- hyde, total phenol, and the activity of catalase and peroxidase enzymes in the same organ was also observed. In contrast, for most of these variables, the opposite results were obtained under VC alone or its interaction with salinity stress. In comparison between two fennel landraces, Shiraz was less affected by salinity stress, while the effect of VC on Urmia was more evi- dent. It can be concluded that VC can limit the adverse effects of salinity stress on fennel by affecting photosynthetic pigments, membrane integrity, minerals concentration, water status, protein content, gibberellins biosyn- thesis, and antioxidants activity

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