Evaluation of <i>Funneliformis mosseae</i> inoculation effects on growth, nutrient uptake, and essential oil content in Turkish oregano under drought stress

Results demonstrated that AMF inoculation significantly improved the fresh and dry weight of <i>O. onites</i> compared to non-inoculated controls (+11% and +16%, respectively). Moreover, AMF-inoculated plants showed notable increases in potassium (+7%) and nitrogen (+12%) contents. The essential oil yield was also significantly higher in AMF-inoculated plants (+3%). Increasing water stress levels significantly decreased the number of AMF spores (-47%) and the percentage of fungal colonization (-57%). Nevertheless, under drought stress mycorrhizal inoculation significantly maintained plant biomass and nutrient uptake comparable to full irrigation. The AMF drought tolerance effects were confirmed at 75%, 50%, and 25% irrigation rates.