Selenium and Arbuscular Mycorrhizal Fungi improve growth, physiological traits, and forage yield of Cichorium intybus cv. Cropmate under water limit conditions

This study evaluated the effects of selenium (Se) application rates (0, 25, 50, and 75 mg/m²) and arbuscular mycorrhizal fungi (AMF) inoculation on growth, forage yield, physiological responses, and tissue Se accumulation of Cichorium intybus cv. Cropmate under controlled water limit conditions. A 4 × 2 factorial pot experiment was conducted with drought stress imposed from 14 days after sowing. Morphological traits were recorded weekly, while forage yield, root traits, chlorophyll content, relative water content, proline, total phenolics, flavonoids, and tissue Se content were determined at harvest. Both Se and AMF significantly affected leaf number, plant height, and stem diameter (P < 0.05), although leaf width remained unaffected. At week VI, the 75 mg Se + AMF maximized height plants, exceeding the control by ~ 63.5%, whereas the 50 mg Se + AMF yielded the highest leaf number (14.40) and stem diameter (15.20 mm). The same combination resulted in the greates fresh forage and crude protein yields, with increases of ~ 51.9% and ~ 170%, respectively, relative to the control (P < 0.05). Selenium application and AMF inoculation together enhanced chlorophyll and relative water content, while lowering proline, phenolic, and flavonoid levels, indicating improved drought tolerance. Tissue Se content increased with increasing Se dose, reaching 0.65 µg/g at the highest rate, while AMF appeared to modulate Se translocation. We conclude that a moderate Se dose (50 mg/m²) combined with AMF offers a promising strategy for chicory biofortification under drought conditions. Field validation and Se speciation analyses are warranted before farm-scale adoption can be recommended.